JPWO2019073828A1 - Conjugated diene rubber - Google Patents

Abstract

A conjugated diene-based rubber comprising a polymer block (A) containing an isoprene monomer unit as a main component and a polymer block (B) containing a 1,3-butadiene monomer unit as a main component. At least one of the polymer block (A) and the polymer block (B) contains a unit of a vinyl compound containing a functional group capable of interacting with silica, and the weight average of the polymer block (A). A conjugated diene-based rubber having a molecular weight (Mw) in the range of 1,000 to 30,000 and an overall weight average molecular weight (Mw) of the conjugated diene-based rubber in the range of 50,000 to 5,000,000. provide.

Description

The present invention relates to a conjugated diene-based rubber, and more specifically, provides a rubber crosslinked product in which adhesion to a roll is effectively suppressed in the case of a rubber composition, low heat generation, and excellent steering stability. Can be related to conjugated diene rubbers.

In recent years, tires for automobiles are strongly required to have low fuel consumption due to environmental problems and resource problems. Since the crosslinked product of the rubber composition containing silica as a filler is superior to the crosslinked product of the rubber composition containing carbon black with respect to rubber, it has excellent rolling resistance when the tire is constructed. It becomes smaller. Therefore, by constructing a tire using a crosslinked rubber product made of a rubber composition containing silica, a tire having excellent fuel efficiency can be obtained.

In the rubber constituting such a rubber composition, various attempts have been made to enhance the affinity between the rubber and silica. For example, in Patent Document 1, when a rubber polymer is obtained by a solution polymerization method, a monomer component containing a silicon-containing vinyl compound is polymerized in addition to a conjugated diene compound by using a specific polymerization initiator. As a result, a technique for giving the rubber itself an affinity with silica is being studied.

International Publication No. 2013/018424

On the other hand, in view of the recent increase in required performance for automobile tires, the tires newly developed in the future have lower heat generation properties than the case where conventional rubbers such as the rubber described in Patent Document 1 are used. There is a demand for a product that can provide an excellent rubber crosslinked product.

The present invention has been made in view of the above problems, and a rubber crosslinked product having a rubber composition in which adhesion to a roll is effectively suppressed, low heat generation, and excellent steering stability can be obtained. It is an object of the present invention to provide a conjugated diene-based rubber which can be given.

As a result of diligent research to achieve the above object, the present inventors have made a conjugated diene-based rubber a polymer block containing an isoprene monomer unit as a main component and having a weight average molecular weight (Mw) in a specific range. , A polymer block containing 1,3-butadiene monomer units as a main component, and at least one of these polymer blocks contains a functional group capable of interacting with silica. It has been found that the above object can be achieved by containing a unit of a vinyl compound, and the present invention has been completed.

That is, according to the present invention, a conjugate comprising a polymer block (A) containing an isoprene monomer unit as a main component and a polymer block (B) containing a 1,3-butadiene monomer unit as a main component. A diene-based rubber, wherein at least one of the polymer block (A) and the polymer block (B) contains a unit of a vinyl compound containing a functional group capable of interacting with silica, and the weight thereof. The weight average molecular weight (Mw) of the coalesced block (A) is in the range of 1,000 to 30,000, and the total weight average molecular weight (Mw) of the conjugated diene rubber is 50,000 to 5,000,000. A range of conjugated diene-based rubbers is provided.

In the conjugated diene rubber of the present invention, the content ratio of the unit of the vinyl compound containing a functional group capable of interacting with the silica is 0 with respect to all the monomer units constituting the conjugated diene rubber. It is preferably 0.01 to 20% by weight.
The conjugated diene rubber of the present invention preferably contains an aromatic vinyl monomer unit in at least one of the polymer block (A) and the polymer block (B).
The conjugated diene rubber of the present invention preferably has a heteroatom-containing functional group at the end of the polymer block (B).

According to the present invention, in any of the above methods for producing a conjugated diene rubber, a monomer (a) containing isoprene is polymerized with a polymerization initiator in an inert solvent to have an active end. The step of forming the coalesced block (A), the polymer block (A) having the active terminal, and the monomer (b) containing 1,3-butadiene are mixed to continue the polymerization reaction, and the polymerization reaction is continued. It comprises a step of obtaining a conjugated diene polymer chain having an active terminal, which comprises a coalesced block (A) and a polymer block (B), and at least one of the monomer (a) or the monomer (b). Provided a method for producing a conjugated diene rubber containing a vinyl compound containing a functional group capable of interacting with silica.
The method for producing a conjugated diene rubber of the present invention preferably further includes a step of reacting a heteroatom-containing compound with the active terminal of the conjugated diene polymer chain having the active terminal.

Further, according to the present invention, there is provided a rubber composition containing silica and a rubber component containing any of the above conjugated diene rubbers.
The rubber composition of the present invention preferably further contains a cross-linking agent.

Further, according to the present invention, a rubber crosslinked product obtained by cross-linking the rubber composition and a tire containing the rubber crosslinked product are provided.

According to the present invention, a conjugated diene-based rubber capable of effectively suppressing adhesion to a roll in the case of a rubber composition, and providing a rubber crosslinked product having low heat generation and excellent steering stability. Can be provided. Further, according to the present invention, it is possible to provide a method for producing such a conjugated diene-based rubber, and a rubber composition, a rubber crosslinked product, and a tire using such a conjugated diene-based rubber.

<Conjugated diene rubber>
The conjugated diene rubber of the present invention includes a polymer block (A) containing an isoprene monomer unit as a main component and a polymer block (B) containing a 1,3-butadiene monomer unit as a main component. ,
At least one of the polymer block (A) and the polymer block (B) contains a unit of a vinyl compound containing a functional group capable of interacting with silica.
The weight average molecular weight (Mw) of the polymer block (A) is in the range of 1,000 to 30,000, and the overall weight average molecular weight (Mw) of the conjugated diene rubber is 50,000 to 5, It is in the range of one million.

According to such a conjugated diene-based rubber of the present invention, adhesion to a roll in the case of a rubber composition is effectively suppressed, and a rubber crosslinked product having low heat generation and excellent steering stability is provided. It is something that can be done.
In particular, in view of the recent increase in required performance for automobile tires, the present inventors have conducted a diligent study on further enhancing low heat generation, and found that conjugated diene-based rubber is mainly composed of isoprene monomer units. A polymer block (A) having a weight average molecular weight (Mw) in a specific range as a component and a polymer block (B) containing a 1,3-butadiene monomer unit as a main component, and these By containing a unit of a vinyl compound containing a functional group capable of interacting with silica in at least one of the polymer blocks of the above, the affinity for a filler such as silica can be further enhanced. As a result, it has been found that the low heat generation property can be further improved, and further, not only the low heat generation property but also the steering stability can be improved. In particular, steering stability can be enhanced by sufficiently exerting the reinforcing property of the filler such as silica. However, by adopting the above configuration, the reinforcing property of the filler such as silica can be sufficiently exhibited. It is thought that this is due to the fact that

Further, as a result of examination by the present inventors in addition to the above, the conjugated diene-based rubber of the present invention having the above constitution has a rubber composition when a filler such as silica is blended to form a rubber composition. When an object is processed into a sheet shape or the like using a roll, it can be considered that adhesion to the roll is effectively suppressed, which is completely different from the improvement of low heat generation, and has an unexpected effect. I also found out what I was doing. In particular, when the rubber composition is processed into a sheet shape or the like using a roll, adhesion to the roll can be effectively suppressed, so that more excellent processability can be realized.

The polymer block (A) may be any as long as it contains an isoprene monomer unit as a main component, and is not particularly limited, and may be composed of only an isoprene monomer unit, or an isoprene monomer. It may consist of a unit and a monomer unit other than the isoprene monomer unit. In this case, as the monomer unit other than the isoprene monomer unit, an aromatic vinyl monomer unit is preferably mentioned, and the polymer block (A) of the present invention is added to the isoprene monomer unit. , It is preferable that it also contains an aromatic vinyl monomer unit.

The content ratio of the isoprene monomer unit in the polymer block (A) is preferably 50% by weight or more, more preferably 70% by weight or more, still more preferably 90% by weight or more. The upper limit of the content ratio of the isoprene monomer unit is not particularly limited, but is preferably 99% by weight or less. By setting the content ratio of the isoprene monomer unit in the polymer block (A) to the above range, when a compounding agent such as silica is blended with the conjugated diene rubber, the compounding agent such as the conjugated diene rubber and silica is blended. The affinity with the rubber can be further enhanced, whereby the obtained rubber crosslinked product can be made more excellent in low heat generation.

Examples of the aromatic vinyl compound for forming the aromatic vinyl monomer unit include styrene, methylstyrene, ethylstyrene, t-butylstyrene, α-methylstyrene, α-methyl-p-methylstyrene, chlorostyrene, and bromo. Examples thereof include styrene, methoxystyrene, dimethylaminomethylstyrene, dimethylaminoethylstyrene, diethylaminomethylstyrene, diethylaminoethylstyrene, cyanoethylstyrene, vinylnaphthalene and the like. Of these, styrene is preferable. The content ratio of the aromatic vinyl monomer unit in the polymer block (A) is preferably 50% by weight or less, more preferably 30% by weight or less, still more preferably 10% by weight or less. The lower limit of the content ratio of the aromatic vinyl monomer unit is not particularly limited, but is preferably 1% by weight or more.

Further, the conjugated diene rubber of the present invention contains a unit of a vinyl compound containing a functional group capable of interacting with silica in at least one of a polymer block (A) and a polymer block (B) described later. Is what you do. In the following, a case where the polymer block (A) contains a unit of a vinyl compound containing a functional group capable of interacting with such silica will be described as an example, but with respect to silica. The unit of the vinyl compound containing the interactable functional group may be contained in at least one of the polymer block (A) and the polymer block (B) described later, and thus can interact with silica. When the unit of the vinyl compound containing a functional group is contained in the polymer block (B) described later, it does not necessarily have to be contained in the polymer block (A).

As a vinyl compound containing a functional group capable of interacting with silica for forming a unit of a vinyl compound containing a functional group capable of interacting with silica, a functional group capable of interacting with silica is used. Any compound containing a group and a vinyl group may be used, and is not particularly limited. Here, the functional group capable of interacting with silica is an intermolecular force (for example, an ion-dipole) that forms a covalent bond between the functional group and the silica surface or is weaker than the covalent bond. It is a functional group capable of forming an interaction, a dipole-dipole interaction, a hydrogen bond, a van der Waals force, etc.). Examples of the functional group capable of interacting with such silica include, but are not limited to, a nitrogen atom-containing functional group, a silicon atom-containing functional group, an oxygen atom-containing functional group, and the like. A silicon atom-containing functional group is preferable from the viewpoint of high interaction.

上記一般式（１）中、Ｘ^１は、化学的な単結合またはヒドロカルビレン基を表し、Ｘ^２、Ｘ^３およびＸ^４は、それぞれ独立して、置換アミノ基、ヒドロカルビルオキシ基、または置換基を有していてもよいヒドロカルビル基を表す。As a preferred embodiment of the vinyl compound containing a functional group capable of interacting with silica, as the vinyl compound containing a silicon atom-containing functional group, for example, a compound represented by the following general formula (1) is preferably used. Can be used.

In the above general formula (1), X ¹ represents a chemical single bond or a hydrocarbylene group, and X ² , X ³ and X ⁴ are independently substituted amino groups, hydrocarbyloxy groups, or substituted groups, respectively. Represents a hydrocarbyl group which may have a group.

In the above general formula (1), X ¹ is a chemical single bond or a hydrocarbylene group, preferably a chemical single bond. Examples of the hydrocarbylene group include an alkylene group, an arcendyl group, an arylene group, and a group in which an arylene group and an alkylene group are bonded.
Examples of the alkylene group include a methylene group, an ethylene group and a trimethylene group. Examples of the alkenyl group include a vinylene group and an ethylene-1,1-diyl group. Examples of the arylene group include a phenylene group, a naphthylene group, and a biphenylene group. Examples of the group in which the arylene group and the alkylene group are bonded include a group in which a phenylene group and a methylene group are bonded, a group in which a phenylene group and an ethylene group are bonded, and the like. When X ¹ is a hydrocarbylene group, X ¹ is preferably an arylene group, more preferably a phenylene group.

In the above general formula (1), X ² , X ³ and X ⁴ each independently represent a substituted amino group, a hydrocarbyloxy group, or a hydrocarbyl group which may have a substituent. Among X ^{2, X 3} and ^{X 4,} is preferably at least one of a substituted amino ^group, of X 2, ^{X 3} and ^{X 4,} and more preferably two of a substituted amino group.

上記一般式（２）中、Ｒ^１およびＲ^２は、互いに結合していても、あるいは、結合していなくてもよく、Ｒ^１およびＲ^２が互いに結合していない場合には、Ｒ^１およびＲ^２は、それぞれ独立して、置換基を有していてもよいヒドロカルビル基、または、トリヒドロカルビルシリル基を表し、Ｒ^１とＲ^２とが互いに結合している場合には、Ｒ^１およびＲ^２は、窒素原子および／または酸素原子を含有していてもよいヒドロカルビレン基を表す。As the substituted amino group that can constitute X ² , X ³ and X ⁴ , the group represented by the following general formula (2) is suitable.

In formula (2), R ¹ and R ² may be bonded to each other, or may not be attached, when R ¹ and R ² are not bonded to each other, R ¹ and R ² independently represents a hydrocarbyl group or a trihydrocarbylsilyl group which may have a substituent, and when R ¹ and R ² are bonded to each other, R ¹ and R are R. ² represents a hydrocarbylene group optionally containing nitrogen and / or oxygen atoms.

Hydrocarbyl groups that can constitute R ¹ and R ² include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, tert-butyl group, and n-pentyl group. , N-Hexyl group, n-octyl group and other chain alkyl groups; cyclic alkyl groups such as cyclopentyl group and cyclohexyl group; aryl groups such as phenyl group, benzyl group and naphthyl group; and the like. Among these, a chain alkyl group is preferable, and a methyl group or an ethyl group is more preferable.
When the hydrocarbyl group capable of constituting R ¹ and R ² has a substituent, a hydrocarbyl group having a hydrocarbyloxy group as a substituent can be mentioned, and the hydrocarbyl group having a hydrocarbyloxy group as a substituent includes methoxy. Examples thereof include an alkoxyalkyl group such as a methyl group, an ethoxymethyl group and a methoxyethyl group; and an aryloxyalkyl group such as a phenoxymethyl group;

Specific examples of the trihydrocarbylsilyl group that can constitute R ¹ and R ² include a trialkylsilyl group such as a trimethylsilyl group, a triethylsilyl group, and a tert-butyldimethylsilyl group.

When R ¹ and R ² are bonded to each other, the hydrocarbylene groups that can form R ¹ and R ² include a trimethylene group, a tetramethylene group, a pentamethylene group, a hexamethylene group, and a heptamethylene group. An alkylene group such as an octamethylene group, a decamethylene group, a dodecamethylene group, a 2,2,4-trimethylhexane-1,6-diyl group; an arcendyl group such as a pentan-2-ene-1,5-diyl group; etc. Can be mentioned. When the hydrocarbylene groups that can constitute R ¹ and R ² contain nitrogen atoms and / or oxygen atoms, the hydrocarbylene group containing nitrogen atoms and / or oxygen atoms is -CH. = N-CH = CH- group represented _{by, -CH = N-CH 2 -CH} 2 - , a group represented _{by, -CH 2 -CH 2 -O-CH} 2 -CH 2 - , a group represented by And so on.
R ¹ and R ² are either an alkyl group, or, it is preferable that a alkylene group bonded with each other R ¹ and R ^2, R ¹ and R ^2, more be an alkyl group Preferably, R ¹ and R ² are more preferably methyl or ethyl groups.

In the above general formula (2), when R ¹ and R ² are hydrocarbyl groups, specific examples of the group represented by the above general formula (2) include a dimethylamino group, a diethylamino group, and an ethylmethylamino group. Dialkylamino groups such as di-n-propylamino group, diisopropylamino group, di-n-butylamino group, diisobutylamino group, di-sec-butylamino group, di-tert-butylamino group; diphenylamino group and the like. Diarylamino group; and the like. Among these, a dialkylamino group is preferable, and a dimethylamino group, a diethylamino group, and a di-n-butylamino group are more preferable.

In the above general formula (2), when R ¹ and R ² are hydrocarbyl groups having a hydrocarbyloxy group as a substituent, a specific example of the group represented by the above general formula (2) is di (methoxy). Examples thereof include a di (alkoxyalkyl) amino group such as a methyl) amino group and a di (ethoxymethyl) amino group.

In the above general formula (2), when R ¹ and R ² are trihydrocarbylsilyl groups, specific examples of the group represented by the above general formula (2) include a bis (trimethylsilyl) amino group and a bis (trimethylsilyl) amino group. Examples thereof include a trialkylsilyl group-containing amino group such as a tert-butyldimethylsilyl) amino group and an N-trimethylsilyl-N-methylamino group.

In the above general formula (2), when R ¹ and R ² are bonded to each other to form a hydrocarbylene group, specific examples of the group represented by the above general formula (2) are 1-. Trimethyleneimino group, 1-pyrrolidino group, 1-piperidino group, 1-hexamethyleneimino group, 1-heptamethyleneimino group, 1-octamethyleneimino group, 1-decamethyleneimino group, 1-dodecamethyleneimino group, etc. 1-alkyleneimino group of 1 and the like.

In the above general formula (2), it is represented by the above general formula (2) when R ¹ and R ² are bonded to each other to form a hydrocarbylene group containing a nitrogen atom and / or an oxygen atom. Specific examples of the group include 1-imidazolyl group, 4,5-dihydro-1-imidazolyl group, morpholino group and the like.

As the group represented by the general formula (2), a dialkylamino group and a 1-alkyleneimino group are preferable, a dialkylamino group is more preferable, and a dimethylamino group, a diethylamino group and a di-n-butylamino group are further preferable. ..

In the general formula ^(1), as the hydrocarbyloxy group capable of constituting the X 2, ^{X 3} and ^{X 4,} a methoxy group, an ethoxy group, n- propoxy group, isopropoxy group, n- butoxy group, sec- butoxy group , Alkoxy groups such as tert-butoxy group; aryloxy groups such as phenoxy group and benzyloxy group; and the like.

In the general formula ^(1), as the hydrocarbyl group may constitute X 2, ^{X 3} and ^{X 4,} methyl group, ethyl group, n- propyl group, an isopropyl group, n- butyl group, sec- butyl group, tert Alkyl groups such as −butyl group; aryl groups such as phenyl group, 4-methyl-1-phenyl group, and benzyl group; and the like.
When the hydrocarbyl group capable of constituting X ² , X ³ and X ⁴ has a substituent, examples thereof include a hydrocarbyl group having a hydrocarbyloxy group, and a methoxymethyl group, an ethoxymethyl group and an ethoxyethyl group. Examples thereof include an alkoxyalkyl group such as.

In the general formula (1), it is represented by the general formula (1) when X ¹ is a chemical single bond and one of X ² , X ³ and X ⁴ is a substituted amino group. Specific examples of the vinyl compound containing a silicon atom-containing functional group include (dimethylamino) dimethylvinylsilane, (ethylmethylamino) dimethylvinylsilane, (di-n-propylamino) dimethylvinylsilane, (diisopropylamino) dimethylvinylsilane, ( (Dialkylamino) dialkylvinylsilanes such as (dimethylamino) diethylvinylsilane, (ethylmethylamino) diethylvinylsilane, (di-n-propylamino) diethylvinylsilane, (diisopropylamino) diethylvinylsilane; [bis (trimethylsilyl) amino] dimethylvinylsilane, [Bis (trialkylsilyl) amino] dialkylvinylsilane such as [bis (t-butyldimethylsilyl) amino] dimethylvinylsilane, [bis (trimethylsilyl) amino] diethylvinylsilane, [bis (t-butyldimethylsilyl) amino] diethylvinylsilane (Dimethylamino) di (methoxymethyl) vinylsilane, (dimethylamino) di (methoxyethyl) vinylsilane, (dimethylamino) di (ethoxymethyl) vinylsilane, (dimethylamino) di (ethoxyethyl) vinylsilane, (diethylamino) di ( (Dialkylamino) di (alkoxyalkyl) vinylsilanes such as methoxymethyl) vinylsilane, (diethylamino) di (methoxyethyl) vinylsilane, (diethylamino) di (ethoxymethyl) vinylsilane, (diethylamino) di (ethoxyethyl) vinylsilane; pyrrolidinodimethyl Cyclic aminodialkylvinylsilane compounds such as vinylsilane, piperidinodimethylvinylsilane, hexamethyleneiminodimethylvinylsilane, 4,5-dihydroimidazolyldimethylvinylsilane, morpholinodimethylvinylsilane; and the like.

In the above general formula (1), silicon represented by the above general formula (1) when X ¹ is a hydrocarbylene group and one of X ² , X ³ and X ⁴ is a substituted amino group. Specific examples of the vinyl compound containing an atomic-containing functional group include (dimethylamino) dimethyl-4-vinylphenylsilane, (dimethylamino) dimethyl-3-vinylphenylsilane, and (diethylamino) dimethyl-4-vinylphenylsilane. (Diethylamino) dimethyl-3-vinylphenylsilane, (di-n-propylamino) dimethyl-4-vinylphenylsilane, (di-n-propylamino) dimethyl-3-vinylphenylsilane, (di-n-butylamino) ) Dimethyl-4-vinylphenylsilane, (di-n-butylamino) dimethyl-3-vinylphenylsilane, (dimethylamino) diethyl-4-vinylphenylsilane, (dimethylamino) diethyl-3-vinylphenylsilane, ( Diethylamino) diethyl-4-vinylphenylsilane, (diethylamino) diethyl-3-vinylphenylsilane, (di-n-propylamino) diethyl-4-vinylphenylsilane, (di-n-propylamino) diethyl-3-vinyl Examples thereof include (dialkylamino) dialkylvinylphenylsilane such as phenylsilane, (di-n-butylamino) diethyl-4-vinylphenylsilane, and (di-n-butylamino) diethyl-3-vinylphenylsilane.

In the above general formula (1), it is represented by the above general formula (1) when X ¹ is a chemical single bond and ^two of X ² , X ³ and X ⁴ are substituted amino groups. Specific examples of the vinyl compound containing a silicon atom-containing functional group include bis (dimethylamino) methylvinylsilane, bis (diethylamino) methylvinylsilane, bis (di-n-propylamino) methylvinylsilane, and bis (di-n-butyl). Bis (dialkylamino) such as amino) methylvinylsilane, bis (dimethylamino) ethylvinylsilane, bis (diethylamino) ethylvinylsilane, bis (di-n-propylamino) ethylvinylsilane, bis (di-n-butylamino) ethylvinylsilane Alkyl vinyl silane; bis [bis (trimethylsilyl) amino] methylvinylsilane, bis [bis (tert-butyldimethylsilyl) amino] methylvinylsilane, bis [bis (trimethylsilyl) amino] ethylvinylsilane, bis [bis (tert-butyldimethylsilyl)) Bis [bis (trialkylsilyl) amino] alkylvinylsilane such as amino] ethylvinylsilane; bis (dimethylamino) methoxymethylvinylsilane, bis (dimethylamino) methoxyethylvinylsilane, bis (dimethylamino) ethoxymethylvinylsilane, bis (dimethylamino) ) Bis (dialkylamino) alkoxyalkylsilanes such as ethoxyethylvinylsilane, bis (diethylamino) methoxymethylvinylsilane, bis (diethylamino) methoxyethylvinylsilane, bis (diethylamino) ethoxymethylvinylsilane, bis (dimethylamino) ethoxyethylvinylsilane; Bis (cyclic amino) alkyl vinyl silane compounds such as pyrrolidino) methyl vinyl silane, bis (piperidino) methyl vinyl silane, bis (hexamethylene imino) methyl vinyl silane, bis (4,5-dihydroimidazolyl) methyl vinyl silane, bis (morpholino) methyl vinyl silane; And so on.

In the above general formula (1), silicon represented by the above general formula (1) when X ¹ is a hydrocarbylene group and ^two of X ² , X ³ and X ⁴ are substituted amino groups. Specific examples of vinyl compounds containing an atomic-containing functional group include bis (dimethylamino) methyl-4-vinylphenylsilane, bis (dimethylamino) methyl-3-vinylphenylsilane, and bis (diethylamino) methyl-4-vinyl. Phenylsilane, bis (diethylamino) methyl-3-vinylphenylsilane, bis (di-n-propylamino) methyl-4-vinylphenylsilane, bis (di-n-propylamino) methyl-3-vinylphenylsilane, bis (Di-n-butylamino) methyl-4-vinylphenylsilane, bis (di-n-butylamino) methyl-3-vinylphenylsilane, bis (dimethylamino) ethyl-4-vinylphenylsilane, bis (dimethylamino) ) Ethyl-3-vinylphenylsilane, bis (diethylamino) ethyl-4-vinylphenylsilane, bis (diethylamino) ethyl-3-vinylphenylsilane, bis (di-n-propylamino) ethyl-4-vinylphenylsilane, Bis (di-n-propylamino) ethyl-3-vinylphenylsilane, bis (di-n-butylamino) ethyl-4-vinylphenylsilane, bis (di-n-butylamino) ethyl-3-vinylphenylsilane Examples thereof include bis (dialkylamino) alkylvinylphenylsilane.

In the above general formula (1), it is represented by the above general formula (1) when X ¹ is a chemical single bond and ^{three of} X ² , X ³ and X ⁴ are substituted amino groups. Specific examples of the vinyl compound containing a silicon atom-containing functional group include tris (dimethylamino) vinylsilane, tris (diethylamino) vinylsilane, tris (di-n-propylamino) vinylsilane, and tris (di-n-butylamino) vinylsilane. Examples thereof include tris (dialkylamino) vinylsilane and the like.

In the above general formula (1), silicon represented by the above general formula (1) when X ¹ is a hydrocarbylene group and ^{three of} X ² , X ³ and X ⁴ are substituted amino groups. Specific examples of the vinyl compound containing an atomic-containing functional group include tris (dimethylamino) -4-vinylphenylsilane, tris (dimethylamino) -3-vinylphenylsilane, tris (diethylamino) -4-vinylphenylsilane, and the like. Tris (diethylamino) -3-vinylphenylsilane, tris (di-n-propylamino) -4-vinylphenylsilane, tris (di-n-propylamino) -3-vinylphenylsilane, tris (di-n-butyl) Examples thereof include tris (dialkylamino) vinylphenylsilane such as amino) -4-vinylphenylsilane and tris (di-n-butylamino) -3-vinylphenylsilane.

In the above general formula (1), silicon represented by the above general formula (1) when X ¹ is a chemical single bond and none of X ² , X ³ and X ⁴ is a substituted amino group. Specific examples of vinyl compounds containing an atomic-containing functional group include trialkoxyvinylsilanes such as trimethoxyvinylsilane, triethoxyvinylsilane and tripropoxyvinylsilane; dialkoxyalkylvinylsilanes such as methyldimethoxyvinylsilane and methyldiethoxyvinylsilane; di (tert). -Dialkoxyarylvinylsilanes such as pentoxy) phenylvinylsilane and di (tert-butoxy) phenylvinylsilane; monoalkoxydialkylvinylsilanes such as dimethylmethoxyvinylsilane; monoalkoxydiarylvinylsilanes such as tert-butoxydiphenylvinylsilane and tert-pentoxydiphenylvinylsilane; Examples thereof include monoalkoxyalkylarylvinylsilanes such as tert-butoxymethylphenylvinylsilane and tert-butoxyethylphenylvinylsilane; substituted alkoxyvinylsilane compounds such as tris (β-methoxyethoxy) vinylsilane; and the like.

Among the compounds represented by the above general formula (1), those in which X ¹ is a chemical single bond are preferable, X ¹ is a chemical single bond, and X ² , X ³ and X ^{4 are formed.} Of these, a compound in which two are substituted amino groups is more preferable, and a compound in which X ¹ is a chemical single bond and ^two of X ² , X ³ and X ⁴ are dialkyl amino groups are particularly preferable. ..

Among the compounds represented by the general formula (1), bis (dimethylamino) methylvinylsilane, bis (diethylamino) methylvinylsilane, and bis (di-n-butylamino) methylvinylsilane are preferable, and bis (diethylamino) methylvinylsilane is preferable. Especially preferable.

In addition to the compound represented by the general formula (1), vinyl compounds containing a functional group capable of interacting with silica include 4-N, N-bis (trimethylsilyl) aminostyrene, and 3-N. , N-bis (trimethylsilyl) aminostyrene and other bis (trialkylsilyl) aminostyrene; 4-bis (trimethylsilyl) aminomethylstyrene, 3-bis (trimethylsilyl) aminomethylstyrene, 4-bis (trimethylsilyl) aminoethylstyrene, Bis (trialkylsilyl) aminoalkylstyrene such as 3-bis (trimethylsilyl) aminoethylstyrene; pyrrolidinoethylstyrene and the like can be mentioned, and among them, pyrrolidinoethylstyrene is preferable. The pyrrolidinoethyl styrene may be an ortho-form, a meta-form, or a para-form, but a meta-form or a para-form is preferable, and a mixture of the meta-form and the para-form is more preferable.

上記一般式（３）中、Ｘ^５は、化学的な単結合またはヒドロカルビレン基を表し、Ｘ^６、Ｘ^７およびＸ^８は、それぞれ独立して、水酸基、置換アミノ基、ヒドロカルビルオキシ基、または置換基を有していてもよいヒドロカルビル基を表す。When a compound represented by the above general formula (1) is used as the vinyl compound containing a functional group capable of interacting with silica, the conjugated diene rubber of the present invention contains silica. On the other hand, as a unit of the vinyl compound containing an interactable functional group, a unit represented by the following general formula (3) will be introduced.

In the above general formula (3), X ⁵ represents a chemical single bond or a hydrocarbylene group, and X ⁶ , X ⁷ and X ⁸ are independent hydroxyl groups, substituted amino groups, and hydrocarbyloxy groups, respectively. Alternatively, it represents a hydrocarbyl group which may have a substituent.

In the unit represented by the general formula (3), X ⁵ corresponds to X ¹ in the compound represented by the general formula (1), and in the unit represented by the general formula (3). , X ⁶ , X ⁷ and X ⁸ correspond to X ² , X ³ and X ⁴ in the compound represented by the above general formula (1), respectively. Therefore, in the unit represented by the general formula (3), X ⁵ , X ⁶ , X ⁷ and X ⁸ are X ¹ , X ² , X ³ and X ¹ , X ² , X ³ in the compound represented by the general formula (1). can be X ⁴ the same as, respectively. Further, when at least one of X ² , X ³ and X ⁴ is a substituted amino group or a hydrocarbyloxy group as the compound represented by the above general formula (1), a substituted amino group is used. , Or the hydrocarbyloxy group can be hydrolyzed at any step and timing to make at least one of X ² , X ³ and X ⁴ a hydroxyl group.

The content ratio of the unit of the vinyl compound containing a functional group capable of interacting with silica in the polymer block (A) is not particularly limited, and is contained in all the monomer units constituting the conjugated diene rubber. It is preferable to adjust the ratio so that it is preferably in the range of 0.01 to 20% by weight, more preferably in the range of 0.02 to 2% by weight, and particularly in the range of 0.05 to 1% by weight. By setting the content ratio of the unit of the vinyl compound containing a functional group that can interact with silica in the above range, the effect of suppressing adhesion to the roll, the effect of reducing heat generation, and the effect of improving steering stability are more remarkable. Can be a compound.

Further, the polymer block (A) is a monomer unit other than the isoprene monomer unit, the aromatic vinyl monomer unit, and the unit of the vinyl compound containing a functional group capable of interacting with silica. May be contained. Other compounds constituting such other monomeric units include chain olefin compounds such as ethylene, propylene and 1-butene; cyclic olefin compounds such as cyclopentene and 2-norbornene; 1,3-butadiene, 2 , 3-Dimethyl-1,3-butadiene, 2-chloro-1,3-butadiene, 1,3-pentadiene, and conjugated diene compounds other than isoprene, such as 1,3-hexadiene; 1,5-hexadiene, 1, Non-conjugated diene compounds such as 6-heptadiene, 1,7-octadien, dicyclopentadiene, and 5-ethylidene-2-norbornene; and the like. The content ratio of the other monomer units in the polymer block (A) is preferably 20% by weight or less, more preferably 10% by weight or less, and further preferably 6% by weight or less. preferable.

The weight average molecular weight (Mw) of the polymer block (A) is in the range of 1,000 to 30,000, preferably in the range of 1,500 to 20,000, more preferably 2,000 to 10, It is in the range of 000. If the weight average molecular weight (Mw) of the polymer block (A) is too small, the effect of suppressing adhesion to the roll, low heat generation, and the effect of improving steering stability cannot be obtained. On the other hand, if the weight average molecular weight (Mw) of the polymer block (A) is too large, the low heat build-up of the obtained rubber crosslinked product is lowered.

Further, the molecular weight distribution represented by the ratio (Mw / Mn) of the weight average molecular weight (Mw) of the polymer block (A) to the number average molecular weight (Mn) is preferably 1.0 to 1.5. More preferably, it is 1.0 to 1.3. When the value (Mw / Mn) of the molecular weight distribution of the polymer block (A) is within the above range, the conjugated diene rubber can be more easily produced. The weight average molecular weight (Mw) and the number average molecular weight (Mn) of the polymer block (A) can be determined as polystyrene-equivalent values by gel permeation chromatography measurement.

The polymer block (B) may be mainly composed of 1,3-butadiene monomer units, and is not particularly limited, and may be composed of only 1,3-butadiene monomer units. Alternatively, it may be composed of a 1,3-butadiene monomer unit and a monomer unit other than the 1,3-butadiene monomer unit. In this case, as the monomer unit other than the 1,3-butadiene monomer unit, the aromatic vinyl monomer unit is preferably mentioned, and the polymer block (B) of the present invention is 1,3-. In addition to the butadiene monomer unit, it preferably contains an aromatic vinyl monomer unit.

The content ratio of the 1,3-butadiene monomer unit in the polymer block (B) is preferably 50% by weight or more, more preferably 55 to 95% by weight, still more preferably 60 to 90% by weight. .. By setting the content ratio of the 1,3-butadiene monomer unit in the polymer block (B) to the above range, the production of the conjugated diene rubber becomes easier.

As the aromatic vinyl compound for forming the aromatic vinyl monomer unit, those exemplified in the above-mentioned explanation of the polymer block (A) can be used, and among the above-mentioned aromatic vinyl compounds, styrene is used. preferable. The content ratio of the aromatic vinyl monomer unit is preferably 50% by weight or less, more preferably 5 to 45% by weight, still more preferably 10 to 40% by weight.

Further, the conjugated diene rubber of the present invention contains a unit of a vinyl compound containing a functional group capable of interacting with silica in at least one of the above-mentioned polymer block (A) and polymer block (B). However, in the conjugated diene-based rubber of the present invention, the unit of the vinyl compound containing a functional group capable of interacting with such silica is contained only in the polymer block (A). , The embodiment contained only in the polymer block (B), or the embodiment contained in both the polymer block (A) and the polymer block (B).

Examples of the vinyl compound containing a functional group capable of interacting with silica for forming a unit of the vinyl compound containing a functional group interactable with silica include the above-mentioned polymer block (A). Those exemplified in the description can be used, and those exemplified as preferable in the above-mentioned description of the polymer block (A) can be preferably used.

The content ratio of the unit of the vinyl compound containing the functional group capable of interacting with silica in the polymer block (B) is not particularly limited, and is contained in all the monomer units constituting the conjugated diene rubber. It is preferable to adjust the ratio so that it is preferably in the range of 0.01 to 20% by weight, more preferably in the range of 0.02 to 2% by weight, and particularly in the range of 0.05 to 1% by weight.

Further, the polymer block (B) is a unit other than the 1,3-butadiene monomer unit, the aromatic vinyl monomer unit, and the vinyl compound unit containing a functional group capable of interacting with silica. It may contain a monomeric unit. Other compounds constituting such other monomer units include isoprene in addition to the same compounds as those exemplified in the polymer block (A) described above (excluding 1,3-butadiene). Can be used. The content ratio of the other monomer units in the polymer block (B) is preferably 40% by weight or less, more preferably 35% by weight or less, and further preferably 25% by weight or less. preferable.

Further, the content ratio of the 1,3-butadiene monomer unit in the entire conjugated diene rubber of the present invention is not particularly limited, and the unit of the vinyl compound containing a functional group capable of interacting with silica is used. The content ratio may be set within the above range, but is preferably 50 to 99.99% by weight, more preferably 55 to 94.98% by weight, based on all the monomer units constituting the conjugated diene rubber. More preferably, it is 60 to 89.95% by weight. Further, the content ratio of the aromatic vinyl monomer unit in the entire conjugated diene rubber of the present invention is not particularly limited, and the content ratio of the unit of the vinyl compound containing the functional group capable of interacting with silica is not particularly limited. The amount may be in the above range, but is preferably 49.99% by weight or less, more preferably 5 to 44.98% by weight, still more preferably 10 with respect to all the monomer units constituting the conjugated diene rubber. ~ 39.95% by weight.

The overall weight average molecular weight (Mw) of the conjugated diene rubber of the present invention is in the range of 50,000 to 5,000,000, preferably in the range of 75,000 to 3,000,000, more preferably. Is in the range of 100,000 to 1,000,000. By setting the overall weight average molecular weight of the conjugated diene rubber within the above range, it becomes easy to blend silica into the rubber composition containing such a conjugated diene rubber, and the processability of the rubber composition is further enhanced. Further, the low heat generation property of the obtained rubber crosslinked product can be further enhanced.

Further, the overall molecular weight distribution represented by the ratio (Mw / Mn) of the total weight average molecular weight (Mw) and the number average molecular weight (Mn) of the conjugated diene rubber of the present invention is 1.1 to 3.0. It is preferably 1.2 to 2.5, and particularly preferably 1.2 to 2.2. By setting the overall molecular weight distribution (Mw / Mn) of the conjugated diene rubber within the above range, the low heat generation property of the obtained rubber crosslinked product can be further improved. The overall weight average molecular weight (Mw) and the overall weight average molecular weight (Mw) of the conjugated diene rubber can be obtained as polystyrene-equivalent values by gel permeation chromatography measurement.

The vinyl bond content in the conjugated diene monomer unit (for example, isoprene monomer unit and 1,3-butadiene monomer unit) in the entire conjugated diene-based rubber of the present invention is preferably 1 to 90 weight by weight. %, More preferably 3 to 85% by weight, particularly preferably 5 to 80% by weight. By setting the vinyl bond content in the conjugated diene monomer unit in the entire conjugated diene rubber within the above range, the obtained rubber crosslinked product can be made more excellent in low heat generation.

The Mooney viscosity (ML _{1 + 4} , 100 ° C.) of the conjugated diene rubber of the present invention is preferably 20 to 100, more preferably 30 to 90, and particularly preferably 35 to 80. When the conjugated diene rubber is an oil-extended rubber, it is preferable that the Mooney viscosity of the oil-extended rubber is in the above range.

The glass transition temperature (Tg) of the conjugated diene rubber of the present invention is not particularly limited, but is preferably 20 to −110 ° C., more preferably 10 to −70 ° C. The glass transition temperature of the conjugated diene-based rubber used in the present invention is determined by, for example, adjusting the aromatic vinyl monomer unit content in the conjugated diene-based rubber and the vinyl bond content in the conjugated diene monomer unit portion. , Can be adjusted as appropriate.

The conjugated diene rubber of the present invention is, for example, a step of polymerizing a monomer (a) containing isoprene in an inert solvent with a polymerization initiator to form a polymer block (A) having an active terminal. ,
The obtained polymer block (A) having an active terminal and the monomer (b) containing 1,3-butadiene are mixed to continue the polymerization reaction, and the polymer block (A) and the polymer block are continued. It can be produced through the step of obtaining a conjugated diene-based polymer chain having an active terminal and comprising (B).

The monomer (a) for forming the polymer block (A) may be any as long as it contains isoprene, and the monomer composition of the polymer block (A) to be formed (the above-mentioned monomer composition). ) May be used. For example, when the polymer block (A) is composed of an isoprene monomer unit and an aromatic vinyl monomer unit, the monomer (a) contains isoprene and an aromatic vinyl compound. And it is sufficient. Further, when the polymer block (A) has a unit of a vinyl compound containing a functional group capable of interacting with silica in addition to the isoprene monomer unit and the aromatic vinyl monomer unit. In addition to the isoprene and the aromatic vinyl compound, the monomer (a) may contain a vinyl compound containing a functional group capable of interacting with silica.

The inert solvent used for the polymerization of the monomer (a) containing isoprene for forming the polymer block (A) is usually used in solution polymerization and does not inhibit the polymerization reaction. If there is, there is no particular limitation. Specific examples of the inert solvent include propane, n-butane, isobutane, n-pentane, isopentane, n-hexane, propene, 1-butene, isobutene, trans-2-butene, cis-2-butene, 1-pentene. , 2-Pentane, 1-Hexene, 2-Hexen, n-heptane and other chain or branched aliphatic hydrocarbons; cyclopentane, cyclohexane and other alicyclic hydrocarbons; benzene, ethylbenzene, toluene, xylene and the like. Aromatic hydrocarbons; ether compounds such as tetrahydrofuran and diethyl ether; and the like. One of these inert solvents may be used alone, or two or more thereof may be used in combination. The amount of the inert solvent used is not particularly limited, but the monomer concentration is, for example, 1 to 80% by weight, preferably 5 to 50% by weight.

As the polymerization initiator used for forming the polymer block (A), as long as it can polymerize the monomer (a) containing isoprene to give a polymer chain having an active terminal. There is no particular limitation. Specific examples thereof include a polymerization initiator using an organic alkali metal compound, an organic alkaline earth metal compound, a lanthanum series metal compound, or the like as a main catalyst. Examples of the organic alkali metal compound include n-butyllithium, sec-butyllithium, t-butyllithium, hexyllithium, phenyllithium, ethyllithium, n-propyllithium, isopropyllithium, tert-octyllithium, and n-decyllithium. , 2-naphthyllithium, 2-butylphenyllithium, 4-phenylbutyllithium, hexyllithium, cycloventyllithium, reaction products of diisopropenylbenzene and butyllithium, organic monolithium compounds such as stillbenlithium; dilithiomethane , 1,4-dilithiobutane, 1,4-dilithio-2-ethylcyclohexane, 1,3,5-trilithiobenzene, 1,3,5-tris (lithiomethyl) benzene, sec-butyllithium and diisopropenylbenzene Organic polyvalent lithium compounds such as reactants of n-butyllithium, 1,3-butadiene and divinylbenzene, reactants of n-butyllithium and polyacetylene compounds; organic sodium compounds such as sodium naphthalene; potassium Examples thereof include organic potassium compounds such as naphthalene; organic rubidium compounds; and organic cesium compounds. In addition, alcoholides such as lithium, sodium and potassium, sulfonates, carbonates, amides and the like can be mentioned. In addition, it may be used in combination with other organometallic compounds. Further, known organic alkali metal compounds disclosed in US Pat. No. 5,708,092, US Pat. No. 2,241,239, US Pat. No. 5,527,753, etc. Can be used.

Examples of the organic alkaline earth metal compound include di-n-butylmagnesium, di-n-hexylmagnesium, diethoxycalcium, calcium distearate, dit-butoxystrontium, diethoxybarium, and diisopropoxybarium. , Diethyl mercaptobarium, dit-butoxybarium, diphenoxybarium, diethylaminobarium, barium distearate, diketylbarium and the like. Examples of the polymerization initiator using a lanthanum-series metal compound as a main catalyst include lanthanum-series metals such as lanthanum, cerium, placeodium, neodym, samarium, and gadrinium, and lanthanum-series metals composed of carboxylic acids and phosphorus-containing organic acids. Examples thereof include a polymerization initiator composed of a salt of the above as a main catalyst and a cocatalyst such as an alkylaluminum compound, an organoaluminum hydride compound, and an organoaluminum halide compound. Among these polymerization initiators, an organic monolithium compound and an organic polyvalent lithium compound are preferably used, and an organic monolithium compound is more preferably used, from the viewpoint of easy industrial availability and easy control of the polymerization reaction. To n-butyllithium is particularly preferably used. The organic alkali metal compound is used as an organic alkali metal amide compound by reacting it with a secondary amine such as dibutylamine, dihexylamine, dibenzylamine, pyrrolidine, piperidine, hexamethyleneimine, and heptamethyleneimine in advance. You may. One of these polymerization initiators may be used alone, or two or more thereof may be used in combination. The organic alkali metal amide compound is not particularly limited, and is, for example, lithium hexamethyleneimide, lithium pyrrolidide, lithium piperidide, lithium heptamethyleneimide, lithium dodecamethyleneimide, lithium dimethylamide, lithium diethylamide, and lithium dibutylamide. , Lithiumdipropylamide, Lithiumdiheptylamide, Lithiumdihexylamide, Lithiumdioctylamide, Lithiumdi-2-ethylhexylamide, Lithiumdidecylamide, Lithium-N-methylpiberazide, Lithiumethylpropylamide, Lithiumethylbutylamide, Lithiumethylbenzyl Examples include amides and lithium methylphenethylamides.

The amount of the polymerization initiator used may be determined according to the target molecular weight, but is preferably 4 to 250 mmol, more preferably 6 to 200 mmol, particularly preferably 6 to 200 mmol per 100 g of the monomer (a) containing isoprene. Is in the range of 10 to 70 mmol.

The polymerization temperature at the time of polymerizing the monomer (a) containing isoprene is preferably in the range of −80 to + 150 ° C., more preferably 0 to 100 ° C., and further preferably 20 to 90 ° C. As the polymerization mode, any mode such as batch type and continuous type can be adopted. Further, when the polymer block (A) is used as a copolymer chain, various bonding modes such as block shape, taper shape, and random shape can be used.

Further, in polymerizing the monomer (a), in order to adjust the vinyl bond content in the isoprene monomer unit in the polymer block (A), a polar compound is added to the inert solvent during the polymerization. Is preferable. Examples of the polar compound include ether compounds such as dibutyl ether, tetrahydrofuran and 2,2-di (tetrahydrofuryl) propane; tertiary amines such as tetramethylethylenediamine; alkali metal alkoxides; phosphine compounds; and the like. Among these, ether compounds and tertiary amines are preferable, tertiary amines are more preferable, and tetramethylethylenediamine is particularly preferable. One of these polar compounds may be used alone, or two or more thereof may be used in combination. The amount of the polar compound used may be determined according to the target vinyl bond content, and is preferably 0.01 to 30 mol, more preferably 0.05 to 10 mol, based on 1 mol of the polymerization initiator. When the amount of the polar compound used is within the above range, the vinyl bond content in the isoprene monomer unit can be easily adjusted, and problems due to deactivation of the polymerization initiator are unlikely to occur. Further, by increasing the amount of the polar compound used within the above range, the vinyl bond content in the isoprene monomer unit can be increased.

The vinyl bond content in the isoprene monomer unit in the polymer block (A) is preferably 3 to 90% by weight, more preferably 5 to 80% by weight. By setting the vinyl bond content in the isoprene monomer unit within the above range, the low heat generation property of the obtained rubber crosslinked product can be further improved. In the present specification, the vinyl bond content in the isoprene monomer unit has an isoprene monomer unit having a 1,2-structure and a 3,4-structure in the isoprene monomer unit. It shall refer to the ratio of the total amount of isoprene monomer units.

Next, the polymer block (A) having an active terminal obtained by polymerizing the monomer (a) containing isoprene and the monomer (b) containing 1,3-butadiene were mixed. By continuing the polymerization reaction, the polymer block (B) can be formed in succession with the polymer block (A), whereby the polymer block (A) and the polymer block (B) are provided. , A conjugated diene polymer chain having an active terminal can be obtained. The formed polymer block (B) has an active terminal, while the active terminal disappears from the polymer block (A).

The monomer (b) for forming the polymer block (B) may be any one containing 1,3-butadiene, and the monomer composition of the polymer block (B) to be formed (described above). A monomer according to the monomer composition) may be used. For example, when the polymer block (B) is composed of 1,3-butadiene monomer unit and aromatic vinyl monomer unit, the monomer (b) includes 1,3-butadiene and It may contain an aromatic vinyl compound. Further, the polymer block (B) has a unit of a vinyl compound containing a functional group capable of interacting with silica in addition to the 1,3-butadiene monomer unit and the aromatic vinyl monomer unit. In the case of this, the monomer (b) shall contain a vinyl compound containing a functional group capable of interacting with silica in addition to 1,3-butadiene and an aromatic vinyl compound. Just do it.

The conjugated diene rubber of the present invention contains at least one of the polymer block (A) and the polymer block (B) described above as a unit of a vinyl compound containing a functional group capable of interacting with silica. Is what you do. Therefore, in the above production method, the monomer (a) containing isoprene used for forming the polymer block (A) and 1,3- used for forming the polymer block (B) are formed. At least one of the butadiene-containing monomer (b) may contain a vinyl compound containing a functional group capable of interacting with silica.

The inert solvent used for the polymerization of the monomer (b) containing 1,3-butadiene in order to form the polymer block (B) is not particularly limited, and is the same as the above-mentioned inert solvent. Can be used.

The amount of the polymer block (A) having an active terminal used in forming the polymer block (B) may be determined according to the target molecular weight, but is a monomer containing 1,3-butadiene. (B) Per 100 g, preferably in the range of 0.1 to 5 mmol, more preferably 0.15 to 2 mmol, still more preferably 0.2 to 1.5 mmol.

The method for mixing the polymer block (A) and the monomer (b) containing 1,3-butadiene is not particularly limited, and the active terminal is contained in the solution of the monomer (b) containing 1,3-butadiene. The polymer block (A) having the above may be added, or the monomer (b) containing 1,3-butadiene may be added to the solution of the polymer block (A) having an active terminal. From the viewpoint of controlling polymerization, a method of adding a polymer block (A) having an active terminal to a solution of the monomer (b) containing 1,3-butadiene is preferable.

The polymerization temperature at the time of polymerizing the monomer (b) containing 1,3-butadiene is preferably in the range of −80 to + 150 ° C., more preferably 0 to 100 ° C., and further preferably 20 to 90 ° C. As the polymerization mode, any mode such as batch type and continuous type can be adopted. When the polymer block (B) is a copolymer chain, a batch type is preferable because it is easy to control the randomness of the bond.

When the polymer block (B) is a copolymer chain, the bonding mode of each monomer can be, for example, various bonding modes such as block-shaped, tapered-shaped, and random-shaped. Of these, the random shape is preferable. By making it random, the low heat generation of the obtained rubber crosslinked product can be further improved.

Further, in order to adjust the vinyl bond content in the 1,3-butadiene monomer unit in the polymer block (B), the vinyl bond content in the isoprene monomer unit in the polymer block (A) is adjusted. As in the case, it is preferable to add a polar compound to the inert solvent during the polymerization. However, when preparing the polymer block (A), an amount of polar compound sufficient to adjust the vinyl bond content in the 1,3-butadiene monomer unit in the polymer block (B) was added to the inert solvent. If is added, it is not necessary to add a new polar compound. As the polar compound used for adjusting the vinyl bond content, the same polar compound as described above can be used. The amount of the polar compound used may be determined according to the target vinyl bond content, and the polymerization initiation used in the initial polymerization reaction (polymerization reaction for forming the first polymer block (A)) may be started. The amount may be adjusted in the range of preferably 0.01 to 100 mol, more preferably 0.1 to 30 mol, per 1 mol of the agent. When the amount of the polar compound used is within this range, the vinyl bond content in the 1,3-butadiene monomer unit can be easily adjusted, and problems due to deactivation of the polymerization initiator are unlikely to occur.

The vinyl bond content in the 1,3-butadiene monomer unit in the polymer block (B) is preferably 1 to 90% by weight, more preferably 3 to 85% by weight, and particularly preferably 5 to 80% by weight. is there. By setting the vinyl bond content in the 1,3-butadiene monomer unit in the polymer block (B) within the above range, the obtained rubber crosslinked product can be made more excellent in low heat generation.

In this way, a conjugated diene-based polymer chain having an active terminal having a polymer block (A) and a polymer block (B) can be obtained. In the present invention, the conjugated diene-based polymer chain having an active terminal is composed of a polymer block (A) -polymer block (B) from the viewpoint of productivity, and the terminal of the polymer block (B). Is preferably the active terminal, but may have a plurality of polymer blocks (A), or may have other polymer blocks. For example, a conjugated diene-based polymer chain having an active terminal such as polymer block (A) -polymer block (B) -polymer block (A) can be mentioned. In this case, the active terminal is formed at the end of the polymer block (A) formed following the polymer block (B). When the polymer block (A) is formed on the active end side of the conjugated diene polymer chain, the amount of isoprene used is the initial polymerization reaction (the polymerization reaction for forming the first polymer block (A)). ), It is preferably 10 to 100 mol, more preferably 15 to 70 mol, and particularly preferably 20 to 35 mol with respect to 1 mol of the polymerization initiator used in.

Then, with respect to the conjugated diene-based polymer chain having an active terminal having a polymer block (A) and a polymer block (B) thus obtained, a coupling agent or a conventionally commonly used coupling agent or A solution of a conjugated diene rubber can be obtained by inactivating the active terminal by adding an alcohol such as methanol, ethanol and isopropanol or a polymerization terminator such as water to the polymerization system.

If desired, the conjugated diene rubber solution obtained as described above is reacted with an antiaging agent such as a phenol-based stabilizer, a phosphorus-based stabilizer, a sulfur-based stabilizer, a crumbing agent, and a scale inhibitor. It is added to the solution, and then the polymerization solvent is separated from the reaction solution by direct drying or steam stripping to recover the solid conjugated diene rubber. Further, if desired, a stretchable oil may be blended to use the conjugated diene rubber as the oil spread rubber. Examples of the spreading oil include paraffin-based, aromatic-based and naphthenic-based petroleum-based softeners, plant-based softeners, and fatty acids. When a petroleum-based softener is used, the content of polycyclic aromatics extracted by the method of IP346 (inspection method of THE INSTITUTE PETROLEUM in the United Kingdom) is preferably less than 3%. When the spreading oil is used, the amount used is usually 5 to 100 parts by weight with respect to 100 parts by weight of the conjugated diene rubber.

Weight ratio of polymer block (A) to polymer block (B) in the conjugated diene rubber of the present invention (when a plurality of polymer blocks (A) and polymer blocks (B) are present, the total of each The weight ratio based on the weight) is (weight of polymer block (A)) / (weight of polymer block (B)), preferably 0.001 to 0.2, and 0.005 to 0.2. It is more preferably 0.1, and particularly preferably 0.01 to 0.05. By setting the weight ratio of the polymer block (A) to the polymer block (B) within the above range, the obtained rubber crosslinked product shall have a good balance between wet grip and low heat generation. Can be done.

Further, the conjugated diene rubber of the present invention may have a polymer chain terminal modified with a heteroatom-containing functional group from the viewpoint of further enhancing the affinity for silica. The heteroatom-containing functional group is not particularly limited as long as it is a group containing a heteroatom, but a group containing at least one selected from a nitrogen atom, an oxygen atom, and a silicon atom is preferable as the heteroatom. A group containing a nitrogen atom or a silicon atom is more preferable, and a group containing a silicon atom is particularly preferable from the viewpoint of affinity for silica.

The heteroatom-containing functional group is, for example, a heteroatom-containing compound at the active end of a conjugated diene-based polymer chain having an active end and having the polymer block (A) and the polymer block (B) obtained by the above production method. Can be introduced into the polymer chain end of the conjugated diene rubber by reacting.

上記一般式（４）中、Ｒ^３〜Ｒ^１０は、炭素数１〜６のアルキル基、または炭素数６〜１２のアリール基であり、これらは互いに同一であっても相違していてもよい。Ｘ^９およびＸ^１２は、炭素数１〜６のアルキル基、炭素数６〜１２のアリール基、炭素数１〜５のアルコキシ基、および、エポキシ基を含有する炭素数４〜１２の基からなる群より選ばれるいずれかの基であり、これらは互いに同一であっても相違していてもよい。Ｘ^１０は、炭素数１〜５のアルコキシ基、またはエポキシ基を含有する炭素数４〜１２の基であり、Ｘ^１０が複数あるときは、それらは互いに同一であっても相違していてもよい。Ｘ^１１は、２〜２０のアルキレングリコールの繰返し単位を含有する基であり、Ｘ^１１が複数あるときは、それらは互いに同一であっても相違していてもよい。ｍは１〜２００の整数、ｎは０〜２００の整数、ｋは０〜２００の整数であり、ｍ＋ｎ＋ｋは１以上である。As the silicon atom-containing compound used when the hetero atom-containing functional group is used as the silicon atom-containing functional group, for example, a siloxane compound can be preferably used. The siloxane compound may be any compound having a siloxane structure (-Si-O-) as a main chain, and is not particularly limited, but an organosiloxane having an organic group in the side chain is preferable, and is represented by the following general formula (4). The polyorganosiloxane to be produced is more preferable.

In the above general formula (4), R ^{3 to} R ¹⁰ are alkyl groups having 1 to 6 carbon atoms or aryl groups having 6 to 12 carbon atoms, and these may be the same or different from each other. .. X ⁹ and X ¹² are composed of an alkyl group having 1 to 6 carbon atoms, an aryl group having 6 to 12 carbon atoms, an alkoxy group having 1 to 5 carbon atoms, and a group having 4 to 12 carbon atoms containing an epoxy group. Any group selected from the group, which may be the same or different from each other. X ¹⁰ is an alkoxy group having 1 to 5 carbon atoms or a group having 4 to 12 carbon atoms containing an epoxy group, and when there are a plurality of X ^10s , they may be the same or different from each other. Good. X ¹¹ is a group containing 2 to 20 repeating units of alkylene glycol, and when there are a plurality of X ¹¹ , they may be the same or different from each other. m is an integer of 1 to 200, n is an integer of 0 to 200, k is an integer of 0 to 200, and m + n + k is 1 or more.

In the polyorganosiloxane represented by the general formula (4), examples of the alkyl group having 1 to 6 carbon atoms which can constitute R ^{3 to} R ¹⁰ , X ⁹ and X ¹² in the general formula (4) include, for example. , Methyl group, ethyl group, n-propyl group, isopropyl group, butyl group, pentyl group, hexyl group, cyclohexyl group and the like. Examples of the aryl group having 6 to 12 carbon atoms include a phenyl group and a methylphenyl group. Among these, a methyl group and an ethyl group are preferable from the viewpoint of easiness of producing the polyorganosiloxane itself.

Further, in the polyorganosiloxane represented by the above general formula (4), examples of the alkoxy group having 1 to 5 carbon atoms that can constitute X ⁹ , X ¹⁰ and X ¹² include a methoxy group, an ethoxy group, and a propoxy group. , Isopropoxy group and butoxy group and the like. Among these, a methoxy group and an ethoxy group are preferable from the viewpoint of easiness of producing the polyorganosiloxane itself.

Further, in the polyorganosiloxane represented by the above general formula (4), as a group having 4 to 12 carbon atoms containing an epoxy group capable of forming X ⁹ , X ¹⁰ and X ¹² , for example, the following general formula ( Examples thereof include groups represented by 5).
−Z ¹ −Z ² −E (5)
In the above general formula (5), Z ¹ is an alkylene group or an alkylarylene group having 1 to 10 carbon atoms, Z ² is a methylene group, a sulfur atom or an oxygen atom, and E is a carbon having an epoxy group. It is a hydrocarbon group of several 2 to 10.

The group represented by the general formula (5) is preferably a Z ² is an oxygen atom, Z ² is an oxygen atom, and is more preferable E is a glycidyl group, Z ¹ is carbon It is particularly preferable that the alkylene group is of the number 1 to 3, where Z ² is an oxygen atom and E is a glycidyl group.

Further, in the polyorganosiloxane represented by the general formula (4), X ⁹ and X ¹² are groups having 4 to 12 carbon atoms containing an epoxy group or groups having 1 to 6 carbon atoms. Alkyl groups are preferred. Further, as X ¹⁰ , among the above, a group having 4 to 12 carbon atoms containing an epoxy group is preferable. Further, it is more preferable that X ⁹ and X ¹² are alkyl groups having 1 to 6 carbon atoms, and X ¹⁰ is a group having 4 to 12 carbon atoms containing an epoxy group.

上記一般式（６）中、ｔは２〜２０の整数であり、Ｘ^１３は炭素数２〜１０のアルキレン基またはアルキルアリーレン基であり、Ｒ^１１は水素原子またはメチル基であり、Ｘ^１４は炭素数１〜１０のアルコキシ基またはアリールオキシ基である。これらの中でも、ｔが２〜８の整数であり、Ｘ^１３が炭素数３のアルキレン基であり、Ｒ^１１が水素原子であり、かつ、Ｘ^１４がメトキシ基であるものが好ましい。Further, in the polyorganosiloxane represented by the general formula (4), the group containing the repeating unit of X ¹¹ , that is, 2 to 20 alkylene glycols is preferably the group represented by the following general formula (6). ..

In the above general formula (6), t is an integer of 2 to 20, X ¹³ is an alkylene group or an alkylarylene group having 2 to 10 carbon atoms, R ¹¹ is a hydrogen atom or a methyl group, and X ¹⁴ is. It is an alkoxy group or an aryloxy group having 1 to 10 carbon atoms. Among these, it is preferable that t is an integer of 2 to 8, X ¹³ is an alkylene group having 3 carbon atoms, R ¹¹ is a hydrogen atom, and X ¹⁴ is a methoxy group.

In the polyorganosiloxane represented by the general formula (4), m is an integer of 1 to 200, preferably an integer of 20 to 150, and more preferably an integer of 30 to 120. When m is 1 to 200, the polyorganosiloxane itself represented by the general formula (4) can be easily produced, its viscosity does not become too high, and it becomes easier to handle.

Further, in the polyorganosiloxane represented by the general formula (4), n is an integer of 0 to 200, preferably an integer of 0 to 150, and more preferably an integer of 0 to 120. k is an integer from 0 to 200, preferably an integer from 0 to 150, and more preferably an integer from 0 to 130. The total number of m, n and k is 1 or more, preferably 3 to 400, more preferably 20 to 300, and particularly preferably 30 to 250. When the total number of m, n and k is 1 or more, the reaction between the polyorganosiloxane represented by the above general formula (4) and the conjugated diene polymer chain having an active terminal is likely to proceed, and further, m When the total number of n and k is 400 or less, the polyorganosiloxane itself represented by the general formula (4) can be easily produced, its viscosity does not become too high, and its handling becomes easy.

上記一般式（７）中、Ｘ^１５〜Ｘ^１７は、それぞれ独立して、−Ｒ^１３で表される基、または−ＯＲ^１４で表される基であり（Ｒ^１３、Ｒ^１４は、炭素数１〜６のアルキル基、または炭素数６〜１２のアリール基であり、好ましくは炭素数１〜６のアルキル基であり、より好ましくはメチル基またはエチル基であり、特に好ましくはメチル基である。）、Ｘ^１５〜Ｘ^１７のうち、少なくとも一つは−ＯＲ^１４で表される基であり、Ｘ^１５〜Ｘ^１７のうち、全てが−ＯＲ^１４で表される基であることが好ましい。また、Ｒ^１２は、炭素数１〜６のアルキレン基であり、好ましくは炭素数２〜５のアルキレン基であり、特に好ましくはトリメチレン基である。Ｘ^１８、Ｘ^１９は、それぞれ独立して、−Ｒ^１５で表される基、または−ＳｉＲ^１６Ｒ^１７Ｒ^１８で表される基であり（Ｒ^１５、Ｒ^１６、Ｒ^１７、Ｒ^１８は、炭素数１〜６のアルキル基、または炭素数６〜１２のアリール基であり、ケイ素原子、窒素原子、または酸素原子を含んでいてもよく、好ましくは炭素数１〜６のアルキル基であり、より好ましくはメチル基またはエチル基であり、特に好ましくはエチル基である。）、Ｘ^１８、Ｘ^１９は、いずれも−Ｒ^１５で表される基であることが好ましい。また、Ｘ^１７とＸ^１９に代わり、上記一般式（７）中のケイ素原子と窒素原子が直接共有結合する様式であってもよい。Further, as the compound containing a silicon atom, a compound represented by the following general formula (7) and a vinyl compound containing a silicon-containing functional group represented by the above general formula (1) can also be preferably used. ..

In the above general formula (7), X ^{15 to} X ¹⁷ are independently groups represented by −R ¹³ or −OR ¹⁴ (R ¹³ and R ¹⁴ are carbon atoms). It is an alkyl group of 1 to 6 or an aryl group having 6 to 12 carbon atoms, preferably an alkyl group having 1 to 6 carbon atoms, more preferably a methyl group or an ethyl group, and particularly preferably a methyl group. ^.), of the X 15 ^{to X 17,} a group of at least one represented by ^{-OR 14,} among the X 15 ^{to X 17,} it is preferably a group all represented by ^{-OR 14.} Further, R ¹² is an alkylene group having 1 to 6 carbon atoms, preferably an alkylene group having 2 to 5 carbon atoms, and particularly preferably a trimethylene group. X ¹⁸ and X ¹⁹ are independent groups represented by -R ¹⁵ or -SiR ¹⁶ R ¹⁷ R ¹⁸ (R ¹⁵ , R ¹⁶ , R ¹⁷ , R ¹⁸ are groups. It is an alkyl group having 1 to 6 carbon atoms or an aryl group having 6 to 12 carbon atoms, which may contain a silicon atom, a nitrogen atom, or an oxygen atom, and is preferably an alkyl group having 1 to 6 carbon atoms. more preferably methyl group or ethyl group, particularly preferably an ethyl ^group.), X 18, X ¹⁹ is preferably both a group represented by -R ^15. Further, instead of X ¹⁷ and X ¹⁹ , a mode in which a silicon atom and a nitrogen atom in the above general formula (7) are directly covalently bonded may be used.

上記一般式（８）中、Ｒ^１９〜Ｒ^２２は、それぞれ独立して、水素原子または炭素数１〜６のアルキル基であり、好ましくは水素原子である。Ｒ^２３は、炭素数１〜６のアルキレン基であり、好ましくは炭素数２〜５のアルキレン基であり、特に好ましくはトリメチレン基である。Ｒ^２４、Ｒ^２５は、それぞれ独立して、水素原子または炭素数１〜６のアルキル基であり、好ましくは炭素数１〜６のアルキル基であり、より好ましくはメチル基またはエチル基であり、特に好ましくはメチル基である。Further, examples of the heteroatom-containing compound other than the compound containing a silicon atom include a compound containing a nitrogen atom, and as such a compound, a compound represented by the following general formula (8) is preferably used. Can be used.

In the above general formula (8), R ^{19 to} R ²² are independently hydrogen atoms or alkyl groups having 1 to 6 carbon atoms, and are preferably hydrogen atoms. R ²³ is an alkylene group having 1 to 6 carbon atoms, preferably an alkylene group having 2 to 5 carbon atoms, and particularly preferably a trimethylene group. R ²⁴ and R ²⁵ are independently hydrogen atoms or alkyl groups having 1 to 6 carbon atoms, preferably alkyl groups having 1 to 6 carbon atoms, and more preferably methyl groups or ethyl groups. Particularly preferably, it is a methyl group.

Examples of the compound containing a nitrogen atom other than the compound represented by the above general formula (8) include N, N'-dimethylurea, N, N'-diethylurea, N, N, N', N. Urea compounds such as'-tetramethylurea, N, N-dimethyl-N', N'-diphenylurea; such as succinimide, N-methylsuccinimide, maleimide, N-methylmaleimide, phthalimide, N-methylphthalimide, etc. Imide compounds; 1,3-diethyl-2-imidazolidinone, 1,3-dimethyl-2-imidazolidinone, 1,1-dipropyl-2-imidazolidinone, 1-methyl-3-ethyl-2-imidazoline Lidinone, 1-methyl-3-propyl-2-imidazolidinone, 1-methyl-3-butyl-2-imidazolidinone, 1-methyl-3- (2-methoxyethyl) -2-imidazolidinone, N-alkyl substituted oxazolidinone compounds such as 1-methyl-3- (2-ethoxyethyl) -2-imidazolidinone, 1,3-di- (2-ethoxyethyl) -2-imidazolidinone; methyl-2- Pyridyl-substituted ketones such as pyridyl ketone, methyl-4-pyridyl ketone, propyl-2-pyridyl ketone, di-4-pyridyl ketone, propyl-3-pyridyl ketone, 2-benzoyl pyridine, 2-vinyl pyridine, 4-vinyl pyridine Compounds and / or pyridyl-substituted vinyl compounds; lactam compounds such as 2-pyrrolidone, N-methylpyrrolidone, N-phenylpyrrolidone, 2-piperidone, 2-quinolone, N-methyl-quinolone, ε-caprolactam and the like. Among these, a lactam compound is preferable, and N-phenylpyrrolidone is more preferable from the viewpoint of further enhancing the low heat build-up of the obtained rubber crosslinked product.

A conjugated diene-based polymer chain having an active terminal having a polymer block (A) and a polymer block (B) obtained by the above production method (hereinafter, appropriately, "conjugated diene-based polymer chain having an active terminal"". The method for reacting the heteroatomic compound with ()) is not particularly limited, and examples thereof include a method of mixing these in a solvent in which each of them can be dissolved. As the solvent used in this case, the solvent exemplified as the inert solvent used in the polymerization of the conjugated diene-based polymer chain having the above-mentioned polymer block (A) and polymer block (B) and having an active terminal is used. be able to. Further, in this case, the heteroatom-containing compound is added to the polymerization solution used for the polymerization for obtaining the conjugated diene-based polymer chain having the polymer block (A) and the polymer block (B) and having an active terminal. The method of addition is simple and preferable. Further, in this case, the heteroatom-containing compound may be dissolved in an inert solvent and added into the polymerization system. The reaction temperature is not particularly limited, but is usually 0 to 120 ° C., and the reaction time is also not particularly limited, but is usually 1 minute to 1 hour.

The amount of the heteroatom-containing compound used in reacting the conjugated diene-based polymer chain having an active terminal with the heteroatom-containing compound forms the first polymerization reaction (the first polymer block (A)). The amount is preferably 0.01 to 10 mol, more preferably 0.1 to 5 mol, based on 1 mol of the polymerization initiator used in the polymerization reaction. When the amount of the heteroatom-containing compound used is within the above range, the low heat build-up of the obtained rubber crosslinked product can be further enhanced. When a siloxane compound such as polyorganosiloxane represented by the general formula (4) is used as the heteroatom-containing compound, the number of moles per siloxane structure (−Si—O−) is within the above range. Is preferable.

The timing of adding the heteroatom-containing compound to the solution containing the conjugated diene polymer chain having an active terminal is not particularly limited, but the polymerization reaction is not completed and the conjugated diene polymer chain having an active terminal is used. The state in which the contained solution also contains a monomer, more specifically, the solution containing a conjugated diene polymer chain having an active terminal is 100 ppm or more, more preferably 300 to 50,000 ppm. It is desirable to add the heteroatomic compound to this solution in the presence of the polymer. By adding the heteroatom-containing compound in this way, it is possible to suppress side reactions between the conjugated diene polymer chain having an active terminal and impurities contained in the polymerization system, and to control the reaction well. It will be possible. When two or more kinds of compounds are used as the heteroatom-containing compound, the timing of adding and reacting these compounds is not particularly limited, and the compounds may be added at the same time and reacted at the same time. Alternatively, when two kinds of compounds are used as the heteroatom-containing compound, only one kind may be added in advance and reacted, and then the remaining one kind may be added and reacted. Further, even when three or more kinds of compounds are used as the heteroatom-containing compound, the addition timing can be set to two steps or three steps or more. In order to further improve the processability of the obtained rubber composition, a heteroatom-containing compound is added to a solution containing a conjugated diene polymer chain having an active terminal, reacted, and then further mixed with an organometallic compound. This may increase the processability of the resulting rubber composition (compound Mooney can be kept low). Further, in this case, after mixing the organometallic compound, a heteroatom-containing compound may be further added and further reacted. Examples of the organic metal compound include n-butyllithium, sec-butyllithium, t-butyllithium, hexyllithium, phenyllithium, ethyllithium, n-propyllithium, isopropyllithium, tert-octyllithium, n-decyllithium, 2-. Examples thereof include naphthyllithium, 2-butylphenyllithium, 4-phenylbutyllithium, hexyllithium, cycloventyllithium, reaction products of diisopropenylbenzene and butyllithium, and organic monolithium compounds such as stillbenlithium.

In this way, by reacting the heteroatom-containing compound with the active end of the conjugated diene polymer chain having an active end, a heteroatom-containing functional group is provided at the end of at least a part of the conjugated diene polymer chain. Can be combined. The conjugated diene-based polymer chain after the reaction has a heteroatom-containing functional group introduced at the end of the polymer chain, but is not modified by the heteroatom-containing functional group and is unmodified. It may contain a conjugated diene-based polymer chain.

As the conjugated diene polymer chain having an active terminal, the end of the polymer block (A) is the active end (for example, polymer block (A) -polymer block (B) -polymer block (A). ) Is used to react a hetero atom-containing compound at the end of the polymer block (A) to introduce a hetero atom-containing functional group at the end of the polymer block (A). Alternatively, a polymer block (B) having an active terminal at the end (for example, a polymer chain represented by the polymer block (A) -polymer block (B)) is used and is heavy. A hetero atom-containing functional group may be introduced at the end of the polymer block (B) by reacting the hetero atom-containing compound at the end of the coalesced block (B). From the viewpoint of further enhancing the low heat build-up of the obtained rubber crosslinked product, by reacting the heteroatom-containing compound at the end of the polymer block (B), a heteroatom-containing functional group is formed at the end of the polymer block (B). It is preferable to introduce a group.

Further, the conjugated diene polymer chain having an active terminal is in a state before the heteroatom-containing compound is reacted with the conjugated diene polymer chain having an active end, or after the heteroatom-containing compound is reacted. As long as the effect of the present invention is not impaired, a part of the active end of the conjugated diene polymer chain having an active end may be used as a coupling agent or the like which has been conventionally used. It may be added into the polymerization system for coupling.

Then, after reacting the heteroatom-containing compound with the conjugated diene-based polymer chain having an active terminal, a polymerization inhibitor such as alcohol such as methanol, ethanol and isopropanol or water is added to the unreacted active terminal. It is preferable to inactivate.

After inactivating the active terminal of the conjugated diene polymer chain, a phenol-based stabilizer, a phosphorus-based stabilizer, and a sulfur-based stabilizer are added to a solution of the conjugated diene-based rubber having a heteroatom-containing functional group at the terminal, if desired. Anti-aging agents, crumbing agents, anti-scale agents, etc. are added to the reaction solution, and then the polymerization solvent is separated from the reaction solution by direct drying or steam stripping, etc., to form a solid, heteroatom-containing functional group. Conjugated diene rubber having a group at the end is recovered. Before separating the polymerization solvent from the reaction solution, the polymerization solution may be mixed with the spreading oil and the conjugated diene rubber may be recovered as the oil spreading rubber. As the spreading oil, those described above can be used in the amounts used described above.

<Rubber composition>
The rubber composition of the present invention is a composition comprising silica in addition to the above-mentioned rubber component containing the conjugated diene-based rubber of the present invention.

The rubber composition of the present invention may contain other rubbers other than the conjugated diene-based rubber of the present invention described above. Other rubbers include, for example, modified natural rubbers (epoxidized natural rubber (ENR), hydride natural rubber (HNR), deproteinized natural rubber (DPNR), high-purity natural rubber (UPNR), grafted natural rubber and the like. (It may be natural rubber), polyisoprene rubber, emulsified polymerized styrene-butadiene copolymer rubber, solution polymerized styrene-butadiene copolymer rubber, polybutadiene rubber (high cis-BR, low cis BR). Further, it may be a polybutadiene rubber containing crystal fibers composed of 1,2-polybutadiene polymer), styrene-isoprene copolymer rubber, butadiene-isoprene copolymer rubber, styrene-isoprene-butadiene copolymer rubber, acrylonitrile-. Among butadiene copolymer rubber, acrylonitrile-styrene-butadiene copolymer rubber, butyl rubber (IIR), ethylene-propylene copolymer, chloroprene rubber, nitrile chloroprene rubber, nitrile isoprene rubber, etc., other than the above-mentioned conjugated diene rubber. Say something. Among these, natural rubber, polyisoprene rubber, polybutadiene rubber, and solution-polymerized styrene-butadiene copolymer rubber are preferable. These rubbers can be used alone or in combination of two or more types such as natural rubber and polybutadiene rubber, natural rubber and styrene-butadiene copolymer rubber.

In the rubber composition of the present invention, the conjugated diene-based rubber of the present invention preferably occupies 10 to 100% by weight of the rubber component in the rubber composition, and particularly preferably 50 to 100% by weight. By including the conjugated diene-based rubber of the present invention in the rubber component at such a ratio, a rubber crosslinked product having low heat generation and excellent steering stability can be obtained.

Examples of the silica used in the present invention include dry method white carbon, wet method white carbon, colloidal silica, precipitated silica, calcium silicate, aluminum silicate and the like. Among these, wet white carbon containing hydrous silicic acid as a main component is preferable. Further, a carbon-silica dual phase filler in which silica is supported on a carbon black surface may be used. These silicas can be used alone or in combination of two or more. Is (measured by the BET method according to ASTM D3037-81) nitrogen adsorption specific surface area of silica used is preferably 20 to 400 m ² / g, more preferably 50~220m ² / g, particularly preferably 80~170m ² / g. The pH of silica is preferably 5 to 10.

The silica used in the present invention preferably has a dibutyl phthalate (DBP) absorption value in the range of about 100 to about 400, particularly preferably in the range of about 150 to about 300.

The silica used in the present invention preferably has an average limit particle size in the range of 0.01 to 0.05 μm as measured by an electron microscope, but the average limit particle size of silica is not limited to this range and is even smaller. Or even larger.

As the silica used in the present invention, for example, various commercially available silicas can be used. For example, PPG Industries Hi-Sil, 210, Hi-Sil233, Hi-Sil243LD; Rhodia ZEOSIL1115MP, ZEOSIL1165MP, ZEOSIL165GR; EVONIK ULTRASIL VN2, ULTR.

The blending amount of silica in the rubber composition of the present invention is preferably 10 to 250 parts by weight, more preferably 15 to 150 parts by weight, still more preferably 20 parts by weight, based on 100 parts by weight of the rubber component in the rubber composition. ~ 130 parts by weight. By setting the blending amount of silica in the above range, it is possible to further improve the low heat generation and steering stability of the obtained rubber crosslinked product.

The rubber composition of the present invention may further contain a silane coupling agent from the viewpoint of further improving low heat generation. The silane coupling agent is not particularly limited, and various silane coupling agents can be used, but in the present invention, a sulfide type, a mercapto type, and a protected mercapto type (for example, those having a carbonylthio group) can be used. , Thiocyanate-based, vinyl-based, amino-based, methacrylate-based, glycidoxy-based, nitro-based, epoxy-based or chloro-based silane coupling agents can be preferably used. Specific examples of the silane coupling agent include bis (3- (triethoxysilyl) propyl) disulfide, bis (3-triethoxysilylpropyl) trisulfide, bis (3- (triethoxysilyl) propyl) tetrasulfide, and γ. -Mercaptopropyltriethoxysilane, 3- [ethoxybis (3,6,9,12,15-pentaoxaoctacosan-1-yloxy) silyl] -1-propanethiol, 3-octanoylthio-1-propyl-triethoxysilane , 3-Trimethoxysilylpropyl-N, N-dimethylthiocarbamoyltetrasulfide, γ-trimethoxysilylpropylbenzothiazyltetrasulfide, 3-trimethoxysilylpropylbenzothiazoletetrasulfide, 3-thiocyanatepropyltriethoxysilane, vinyl Triethoxysilane, N- (β-aminoethyl) -γ-aminopropyltrimethoxysilane, 3-trimethoxysilylpropylmethacrylate monosulfide, γ-glycidoxypropyltriethoxysilane, 3-nitropropyltrimethoxysilane, β -(3,4-Epoxycyclohexyl) ethyltrimethoxysilane, 3-chloropropyltrimethoxysilane and the like can be mentioned. In addition, NXT-Z100, NXT-Z30, NXT-Z45, NXT-Z60, NXT-Z45, NXT manufactured by Momentive Performance Materials, Si69, Si75, VP Si363 manufactured by Evonik Degussa, etc. can also be used. it can. These silane coupling agents can be used alone or in combination of two or more. Further, one or more of these may be oligomerized in advance and used in the oligomerized state. The blending amount of the silane coupling agent is preferably 0.1 to 30 parts by weight, more preferably 1 to 15 parts by weight, based on 100 parts by weight of silica.

Further, the rubber composition of the present invention may further contain carbon black such as furnace black, acetylene black, thermal black, channel black, and graphite. Of these, furnace black is preferred. Each of these carbon blacks can be used alone or in combination of two or more. The blending amount of carbon black is usually 120 parts by weight or less with respect to 100 parts by weight of the rubber component in the rubber composition.

The method of adding silica to the rubber component containing the conjugated diene rubber of the present invention is not particularly limited, and a method of adding and kneading the solid rubber component (dry kneading method) or a conjugated diene rubber A method of adding to a solution containing (wet kneading method) or the like to coagulate and dry the rubber can be applied.

Moreover, it is preferable that the rubber composition of the present invention further contains a cross-linking agent. Examples of the cross-linking agent include sulfur-containing compounds such as sulfur and sulfur halide, organic peroxides, quinonedioximes, organic polyvalent amine compounds, and alkylphenol resins having a methylol group. Of these, sulfur is preferably used. The amount of the cross-linking agent blended is preferably 0.1 to 15 parts by weight, more preferably 0.5 to 5 parts by weight, and particularly preferably 1 to 4 parts by weight, based on 100 parts by weight of the rubber component in the rubber composition. Is.

Further, in addition to the above components, the rubber composition of the present invention contains a cross-linking accelerator, a cross-linking activator, an antioxidant, a filler (excluding the above-mentioned silica and carbon black), an activator, and a process oil according to a conventional method. , Plasticizers, lubricants, tackifiers, etc. can be blended in the required amounts.

When sulfur or a sulfur-containing compound is used as the cross-linking agent, it is preferable to use a cross-linking accelerator and a cross-linking activator in combination. Examples of the cross-linking accelerator include sulfenamide-based cross-linking accelerator; guanidine-based cross-linking accelerator; thiourea-based cross-linking accelerator; thiazole-based cross-linking accelerator; thiuram-based cross-linking accelerator; dithiocarbamic acid-based cross-linking accelerator; xanthate-based Crosslink accelerators; and the like. Among these, those containing a sulfenamide-based cross-linking accelerator are preferable. These cross-linking accelerators may be used alone or in combination of two or more. The amount of the cross-linking accelerator to be blended is preferably 0.1 to 15 parts by weight, more preferably 0.5 to 5 parts by weight, and particularly preferably 1 to 4 parts by weight, based on 100 parts by weight of the rubber component in the rubber composition. It is a department.

Examples of the cross-linking activator include higher fatty acids such as stearic acid; zinc oxide; and the like. These cross-linking activators may be used alone or in combination of two or more. The blending amount of the cross-linking activator is preferably 0.05 to 20 parts by weight, particularly preferably 0.5 to 15 parts by weight, based on 100 parts by weight of the rubber component in the rubber composition.

In order to obtain the rubber composition of the present invention, each component may be kneaded according to a conventional method. For example, a component excluding a heat-unstable component such as a cross-linking agent or a cross-linking accelerator is kneaded with a conjugated diene rubber. After that, a heat-labile component such as a cross-linking agent or a cross-linking accelerator can be mixed with the kneaded product to obtain a desired composition. The kneading temperature of the components excluding the heat-unstable component and the conjugated diene rubber is preferably 80 to 200 ° C., more preferably 120 to 180 ° C., and the kneading time is preferably 30 seconds to 30 minutes. is there. Further, the kneaded product and the heat-unstable component are usually mixed after cooling to 100 ° C. or lower, preferably 80 ° C. or lower.

<Rubber crosslinked product>
The rubber crosslinked product of the present invention is obtained by cross-linking the above-mentioned rubber composition of the present invention.
The rubber crosslinked product of the present invention is formed by using the rubber composition of the present invention, for example, by a molding machine corresponding to a desired shape, for example, an extruder, an injection molding machine, a compressor, a roll, or the like, and is heated. It can be produced by carrying out a cross-linking reaction and fixing the shape as a rubber cross-linked product. In this case, it may be crosslinked after being molded in advance, or may be crosslinked at the same time as molding. The molding temperature is usually 10 to 200 ° C, preferably 25 to 120 ° C. The crosslinking temperature is usually 100 to 200 ° C., preferably 130 to 190 ° C., and the crosslinking time is usually 1 minute to 24 hours, preferably 2 minutes to 12 hours, particularly preferably 3 minutes to 6 hours. ..

Further, depending on the shape and size of the rubber crosslinked product, even if the surface is crosslinked, it may not be sufficiently crosslinked to the inside, so that it may be further heated for secondary crosslinking.

As the heating method, a general method used for cross-linking rubber such as press heating, steam heating, oven heating, and hot air heating may be appropriately selected.

Since the rubber crosslinked product of the present invention thus obtained is obtained by using the conjugated diene-based rubber of the present invention described above, it is excellent in low heat generation and steering stability. In particular, the conjugated diene-based rubber of the present invention contains a polymer block (A) containing an isoprene monomer unit as a main component and having a weight average molecular weight (Mw) in a specific range, and a 1,3-butadiene monomer unit. It is provided with a polymer block (B) containing the above as a main component, and at least one of these polymer blocks contains a unit of a vinyl compound containing a functional group capable of interacting with silica. Therefore, due to the action of the unit of the vinyl compound containing the functional group capable of interacting with the polymer block (A) and silica, the affinity for the filler such as silica is high, and thereby the filler such as silica. Can be satisfactorily dispersed, and further, the reinforcing property of a filler such as silica can be sufficiently exhibited. Therefore, the rubber crosslinked product of the present invention obtained by using the conjugated diene-based rubber of the present invention has excellent low heat generation and steering stability.

The rubber crosslinked product of the present invention makes use of its excellent low heat generation and steering stability. For example, in a tire, the material of each part of the tire such as cap tread, base tread, carcass, sidewall, bead part; hose, belt , Matte, anti-vibration rubber, and other materials for various industrial products; resin impact resistance improver; resin film buffer; sole; rubber shoes; golf balls; toys; etc. In particular, the crosslinked rubber product of the present invention is excellent in low heat generation and steering stability, and therefore can be suitably used as a material for tires, particularly fuel-efficient tires, and is most suitable for tread applications.

Hereinafter, the present invention will be described based on more detailed examples, but the present invention is not limited to these examples. In the following, "part" is based on weight unless otherwise specified. The tests and evaluations were as follows.

[Weight average molecular weight, molecular weight distribution]
The weight average molecular weight (Mw) and the molecular weight distribution (Mw / Mn) were determined by obtaining a chart based on the polystyrene-equivalent molecular weight by gel permeation chromatography and based on the obtained chart. The specific measurement conditions for gel permeation chromatography were as follows.
Measuring machine: High-performance liquid chromatograph (manufactured by Tosoh, trade name "HLC-8220")
Column: Two Tosoh products, trade name "GMH-HR-H", were connected in series.
Detector: Differential refractometer Eluent: Tetrahydrofuran Column temperature: 40 ° C

[Micro structure]
The styrene monomer unit content, the bis (diethylamino) methylvinylsilane monomer unit content, and the vinyl bond content were measured by ¹ H-NMR.

[Roll adhesion of rubber composition]
The obtained rubber composition was molded with an open roll at 50 ° C. to form a sheet. The state of the sheet-shaped rubber composition obtained at this time when peeled from the surface of the open roll was evaluated according to the following criteria.
⊚: When the rubber composition was peeled off from the surface of the open roll, it did not adhere to the roll and could be easily peeled off. Further, since the adhesion to the roll did not occur, the surface of the sheet-shaped rubber composition was sufficiently smooth.
X: When the rubber composition was peeled off from the surface of the open roll, it adhered strongly to the roll and was difficult to peel off. In addition, the sheet-like rubber composition was inferior in surface smoothness because it adhered severely to the roll.

[Wet grip of crosslinked rubber]
For wet grip, a test piece of a rubber crosslinked product having a length of 50 mm, a width of 12.7 mm and a thickness of 2 mm was used at 0 ° C. under the conditions of dynamic strain of 0.5% and 10 Hz using ARES manufactured by Leometrics. It was evaluated by measuring the value of tan δ. The value of tan δ is shown as an index with the measured value of Comparative Example 3 as 100. The larger this index is, the better the wet grip property is.

[Low heat generation of crosslinked rubber]
For low heat generation, a test piece of a rubber crosslinked product having a length of 50 mm, a width of 12.7 mm, and a thickness of 2 mm was used at 60 ° C. under the conditions of dynamic strain 2.5% and 10 Hz using ARES manufactured by Leometrics. It was evaluated by measuring tan δ. Regarding the value of tan δ, Examples 1 to 9 and Comparative Examples 1 and 2 are indicated by an index having the measured value of Comparative Example 3 as 100, and Example 10 is indicated by an index having the measured value of Comparative Example 4 being 100. , Examples 11 and 12, and Comparative Examples 6 and 7 are shown by an index with the measured value of Comparative Example 5 as 100. The smaller this index, the better the low heat generation.

[Rubber cross-linked steering stability]
Steering stability is evaluated by conducting a tensile test on the test piece of the rubber crosslinked product in accordance with JIS K6301 and measuring and calculating the values of (stress at 300% elongation) / (stress at 100% elongation). did. The larger this value is, the higher the reinforcing property by silica is and the better the steering stability is.

[Production Example 1] Preparation of polymer block (A1) having an active terminal 140.8 g of cyclohexane and 3.0 mmol of tetramethylethylenediamine were added to an 800 ml container substituted with nitrogen, and further, 30.0 mmol of n-butyllithium was added. Was added. Then, 113.6 g of isoprene and 9.2 g of styrene were slowly added and reacted in a container at 50 ° C. for 120 minutes to obtain a polymer block (A1) having an active terminal. The weight average molecular weight (Mw) of this polymer block (A1) is 6,500, the molecular weight distribution (Mw / Mn) is 1.10, the styrene monomer unit content is 7.5% by weight, and the isoprene monomer unit. The content was 92.5% by weight and the vinyl bond content was 7.0% by weight.

[Production Example 2] Preparation of polymer block (A2) having an active terminal To a nitrogen-substituted 800 ml container, 134.3 g of cyclohexane and 1.0 mmol of tetramethylethylenediamine were added, and 10.0 mmol of n-butyllithium was further added. Was added. Then, 36.1 g of isoprene and 2.9 g of styrene were slowly added and reacted in a container at 50 ° C. for 120 minutes to obtain a polymer block (A2) having an active terminal. The weight average molecular weight (Mw) of this polymer block (A2) is 5,700, the molecular weight distribution (Mw / Mn) is 1.09, the styrene monomer unit content is 7.4% by weight, and the isoprene monomer unit. The content was 92.6% by weight and the vinyl bond content was 7.3% by weight.

[Example 1]
In an autoclave with a stirrer, under a nitrogen atmosphere, 792 g of cyclohexane, 0.71 mmol of tetramethylethylenediamine, 76.3 g of 1,3-butadiene, 28.7 g of styrene, and bis (diethylamino) methylvinylsilane (X in the above general formula (1)). After charging 0.144 g of ¹ = chemical single bond, X ² , X ³ = diethylamino group, X ⁴ = methyl group), the polymer block having an active terminal obtained in Production Example 1 above. 0.51 mmol of (A1) was converted into a lithium atom content, and polymerization was started at 60 ° C. After continuing the polymerization reaction for 60 minutes and confirming that the polymerization conversion rate was in the range of 95% to 100%, the amount of methanol corresponding to twice the molar amount of n-butyllithium used as the polymerization inhibitor was used. Was added to obtain a solution containing a conjugated diene-based rubber. In this solution, 0.15 part of anti-aging agent (trade name "Irganox 1520L", manufactured by BASF) was added to 100 parts of conjugated diene rubber, and extension oil (trade name "Aromax T-DAE"). JX Nikko Nisseki Energy Co., Ltd.) was added in 37.5 parts to 100 parts of conjugated diene rubber, the solvent was removed by steam stripping, and the mixture was vacuum dried at 60 ° C. for 24 hours to form a solid state. Conjugated diene rubber was obtained. The weight average molecular weight (Mw) of the obtained conjugated diene rubber of Example 1 was 431,000, the styrene monomer unit content was 27% by weight, and the vinyl bond content was 59% by weight. Further, the content of the bis (diethylamino) methylvinylsilane monomer unit in the obtained conjugated diene rubber of Example 1 was 0.15% by weight.

[Example 2]
792 g of cyclohexane, 0.71 mmol of tetramethylethylenediamine, 76.3 g of 1,3-butadiene, 28.7 g of styrene, and 0.144 g of bis (diethylamino) methylvinylsilane were charged into an autoclave with a stirrer under a nitrogen atmosphere, and then the above production was performed. The polymer block (A1) having an active terminal obtained in Example 1 was added in an amount of 0.51 mmol in terms of lithium atom content, and polymerization was started at 60 ° C. Was continued for 60 minutes the polymerization reaction, the polymerization conversion rate confirms that it is now in the range of 95% 100%, N, at the N- dimethylaminopropyl acrylamide (the general formula ^{(8), R} 19 to R ⁽ Compound ²² = hydrogen atom, R ²³ = trimethylene group, R ²⁴ , R ²⁵ = methyl group) 0.35 mmol was added and reacted for 30 minutes. Then, as a polymerization inhibitor, methanol corresponding to twice the mole of n-butyllithium used was added to obtain a solution containing a conjugated diene rubber. In this solution, 0.15 part of anti-aging agent (trade name "Irganox 1520L", manufactured by BASF) was added to 100 parts of conjugated diene rubber, and extension oil (trade name "Aromax T-DAE"). JX Nikko Nisseki Energy Co., Ltd.) was added in 37.5 parts to 100 parts of conjugated diene rubber, the solvent was removed by steam stripping, and the mixture was vacuum dried at 60 ° C. for 24 hours to form a solid state. Conjugated diene rubber was obtained. The weight average molecular weight (Mw) of the obtained conjugated diene rubber of Example 2 was 380,000, the styrene monomer unit content was 27% by weight, and the vinyl bond content was 59% by weight. Further, the content of the bis (diethylamino) methylvinylsilane monomer unit in the obtained conjugated diene rubber of Example 2 was 0.15% by weight.

[Example 3]
792 g of cyclohexane, 0.71 mmol of tetramethylethylenediamine, 76.3 g of 1,3-butadiene, 28.7 g of styrene, and 0.144 g of bis (diethylamino) methylvinylsilane were charged into an autoclave with a stirrer under a nitrogen atmosphere, and then the above production was performed. The polymer block (A1) having an active terminal obtained in Example 1 was added in an amount of 0.51 mmol in terms of lithium atom content, and polymerization was started at 60 ° C. After continuing the polymerization reaction for 60 minutes and confirming that the polymerization conversion rate was in the range of 95% to 100%, the polyorganosiloxane represented by the following formula (9) was repeatedly subjected to −Si—O−. It was added so as to be 0.65 mmol in terms of the number of units, and reacted for 30 minutes. Then, as a polymerization inhibitor, methanol corresponding to twice the mole of n-butyllithium used was added to obtain a solution containing a conjugated diene rubber. In this solution, 0.15 part of anti-aging agent (trade name "Irganox 1520L", manufactured by BASF) was added to 100 parts of conjugated diene rubber, and extension oil (trade name "Aromax T-DAE"). JX Nikko Nisseki Energy Co., Ltd.) was added in 37.5 parts to 100 parts of conjugated diene rubber, the solvent was removed by steam stripping, and the mixture was vacuum dried at 60 ° C. for 24 hours to form a solid state. Conjugated diene rubber was obtained. The weight average molecular weight (Mw) of the obtained conjugated diene rubber of Example 3 was 827,000, the styrene monomer unit content was 27% by weight, and the vinyl bond content was 59% by weight. Further, the content of bis (diethylamino) methylvinylsilane monomer unit in the obtained conjugated diene rubber of Example 3 was 0.15% by weight.

[Example 4]
792 g of cyclohexane, 0.71 mmol of tetramethylethylenediamine, 76.3 g of 1,3-butadiene, 28.7 g of styrene, and 0.144 g of bis (diethylamino) methylvinylsilane were charged into an autoclave with a stirrer under a nitrogen atmosphere, and then the above production was performed. The polymer block (A1) having an active terminal obtained in Example 1 was added in an amount of 0.51 mmol in terms of lithium atom content, and polymerization was started at 60 ° C. After continuing the polymerization reaction for 60 minutes and confirming that the polymerization conversion rate was in the range of 95% to 100%, the polyorganosiloxane represented by the above general formula (9) was subjected to −Si—O−. The mixture was added so as to have 1.68 mmol in terms of the number of repeating units, and the mixture was reacted for 20 minutes. Then, 0.89 mmol of n-butyllithium was added and the reaction was carried out for 10 minutes. Next, the polyorganosiloxane represented by the general formula (9) was added so as to be 0.49 mmol in terms of the number of repeating units of −Si—O—, and the reaction was carried out for 20 minutes. Then, as a polymerization inhibitor, methanol corresponding to twice the mole of n-butyllithium used was added to obtain a solution containing a conjugated diene rubber. In this solution, 0.15 part of anti-aging agent (trade name "Irganox 1520L", manufactured by BASF) was added to 100 parts of conjugated diene rubber, and extension oil (trade name "Aromax T-DAE"). JX Nikko Nisseki Energy Co., Ltd.) was added in 37.5 parts to 100 parts of conjugated diene rubber, the solvent was removed by steam stripping, and the mixture was vacuum dried at 60 ° C. for 24 hours to form a solid state. Conjugated diene rubber was obtained. The weight average molecular weight (Mw) of the obtained conjugated diene rubber of Example 4 was 563,000, the styrene monomer unit content was 27% by weight, and the vinyl bond content was 59% by weight. Further, the content of the bis (diethylamino) methylvinylsilane monomer unit in the obtained conjugated diene rubber of Example 4 was 0.15% by weight.

[Example 5]
792 g of cyclohexane, 0.71 mmol of tetramethylethylenediamine, 76.3 g of 1,3-butadiene, 28.7 g of styrene, and 0.144 g of bis (diethylamino) methylvinylsilane were charged into an autoclave with a stirrer under a nitrogen atmosphere, and then the above production was performed. The polymer block (A1) having an active terminal obtained in Example 1 was added in an amount of 0.51 mmol in terms of lithium atom content, and polymerization was started at 60 ° C. The polymerization reaction was continued for 60 minutes, and after confirming that the polymerization conversion was in the range of 95% to 100%, 0.89 mmol of n-butyllithium was added and the reaction was carried out for 10 minutes. Next, the polyorganosiloxane represented by the general formula (9) was added so as to be 2.17 mmol in terms of the number of repeating units of −Si—O—, and the reaction was carried out for 30 minutes. Then, as a polymerization inhibitor, methanol corresponding to twice the mole of n-butyllithium used was added to obtain a solution containing a conjugated diene rubber. In this solution, 0.15 part of anti-aging agent (trade name "Irganox 1520L", manufactured by BASF) was added to 100 parts of conjugated diene rubber, and extension oil (trade name "Aromax T-DAE"). JX Nikko Nisseki Energy Co., Ltd.) was added in 37.5 parts to 100 parts of conjugated diene rubber, the solvent was removed by steam stripping, and the mixture was vacuum dried at 60 ° C. for 24 hours to form a solid state. Conjugated diene rubber was obtained. The weight average molecular weight (Mw) of the obtained conjugated diene rubber of Example 5 was 617,000, the styrene monomer unit content was 27% by weight, and the vinyl bond content was 59% by weight. Further, the content of the bis (diethylamino) methylvinylsilane monomer unit in the obtained conjugated diene rubber of Example 5 was 0.15% by weight.

[Example 6]
792 g of cyclohexane, 0.71 mmol of tetramethylethylenediamine, 76.3 g of 1,3-butadiene, 28.7 g of styrene, and 0.144 g of bis (diethylamino) methylvinylsilane were charged into an autoclave with a stirrer under a nitrogen atmosphere, and then the above production was performed. The polymer block (A1) having an active terminal obtained in Example 1 was added in an amount of 0.51 mmol in terms of lithium atom content, and polymerization was started at 60 ° C. It was continued for 60 minutes the polymerization reaction, the polymerization conversion rate confirms that it is now in the range of 95% to 100% in 3-diethylamino-propyl trimethoxysilane (the general formula (7), R ^{12 =} trimethylene group , X ¹⁵ , X ¹⁶ , X ¹⁷ = methoxy group, X ¹⁸ , X ¹⁹ = ethyl group compound) 0.35 mmol was added and reacted for 20 minutes. Then 0.61 mmol of n-butyllithium was added and reacted for 30 minutes. Then, as a polymerization inhibitor, methanol corresponding to twice the mole of n-butyllithium used was added to obtain a solution containing a conjugated diene rubber. In this solution, 0.15 part of anti-aging agent (trade name "Irganox 1520L", manufactured by BASF) was added to 100 parts of conjugated diene rubber, and extension oil (trade name "Aromax T-DAE"). JX Nikko Nisseki Energy Co., Ltd.) was added in 37.5 parts to 100 parts of conjugated diene rubber, the solvent was removed by steam stripping, and the mixture was vacuum dried at 60 ° C. for 24 hours to form a solid state. Conjugated diene rubber was obtained. The weight average molecular weight (Mw) of the obtained conjugated diene rubber of Example 6 was 295,000, the styrene monomer unit content was 27% by weight, and the vinyl bond content was 59% by weight. Further, the content of bis (diethylamino) methylvinylsilane monomer unit in the obtained conjugated diene rubber of Example 6 was 0.15% by weight.

[Example 7]
In Example 6, a solid conjugated diene rubber was obtained in the same manner as in Example 6 except that the amount of bis (diethylamino) methylvinylsilane used was changed to 0.072 g. The weight average molecular weight (Mw) of the obtained conjugated diene rubber of Example 7 was 311,000, the styrene monomer unit content was 27% by weight, and the vinyl bond content was 59% by weight. Further, the content of bis (diethylamino) methylvinylsilane monomer unit in the obtained conjugated diene rubber of Example 7 was 0.075% by weight.

[Comparative Example 1]
In an autoclave with a stirrer, 792 g of cyclohexane, 0.71 mmol of tetramethylethylenediamine, 76.3 g of 1,3-butadiene, and 28.7 g of styrene were charged under a nitrogen atmosphere, and then the active terminal obtained in Production Example 1 above was added. The polymer block (A1) having the polymer block (A1) was added in an amount of 0.51 mmol in terms of lithium atom content, and polymerization was started at 60 ° C. After continuing the polymerization reaction for 60 minutes and confirming that the polymerization conversion rate was in the range of 95% to 100%, the amount of methanol corresponding to twice the molar amount of n-butyllithium used as the polymerization inhibitor was used. Was added to obtain a solution containing a conjugated diene-based rubber. In this solution, 0.15 part of anti-aging agent (trade name "Irganox 1520L", manufactured by BASF) was added to 100 parts of conjugated diene rubber, and extension oil (trade name "Aromax T-DAE"). JX Nikko Nisseki Energy Co., Ltd.) was added in 37.5 parts to 100 parts of conjugated diene rubber, the solvent was removed by steam stripping, and the mixture was vacuum dried at 60 ° C. for 24 hours to form a solid state. Conjugated diene rubber was obtained. The weight average molecular weight (Mw) of the obtained conjugated diene rubber of Comparative Example 1 was 443,000, the styrene monomer unit content was 27% by weight, and the vinyl bond content was 59% by weight.

[Comparative Example 2]
An autoclave with a stirrer was charged with 792 g of cyclohexane, 0.71 mmol of tetramethylethylenediamine, 76.3 g of 1,3-butadiene, 28.7 g of styrene, and 0.144 g of bis (diethylamino) methylvinylsilane under a nitrogen atmosphere, and then 3-. Compound obtained by reacting (dimethylamino) propyl lithium with isoprene [Reaction ratio: isoprene / 3- (dimethylamino) propyl lithium = 2/1 (molar ratio), manufactured by FMC, trade name "AI-200CE2", molecular weight = 229, a compound represented by the following formula (10)] was added in an amount of 0.51 mmol, and polymerization was started at 60 ° C. After continuing the polymerization reaction for 60 minutes and confirming that the polymerization conversion rate was in the range of 95% to 100%, the amount of methanol corresponding to twice the molar amount of n-butyllithium used as the polymerization inhibitor was used. Was added to obtain a solution containing a conjugated diene-based rubber. In this solution, 0.15 part of anti-aging agent (trade name "Irganox 1520L", manufactured by BASF) was added to 100 parts of conjugated diene rubber, and extension oil (trade name "Aromax T-DAE"). JX Nikko Nisseki Energy Co., Ltd.) was added in 37.5 parts to 100 parts of conjugated diene rubber, the solvent was removed by steam stripping, and the mixture was vacuum dried at 60 ° C. for 24 hours to form a solid state. Conjugated diene rubber was obtained. The weight average molecular weight (Mw) of the obtained conjugated diene rubber of Comparative Example 2 was 400,000, the styrene monomer unit content was 27% by weight, and the vinyl bond content was 59% by weight. The bis (diethylamino) methylvinylsilane monomer unit content in the obtained conjugated diene rubber of Comparative Example 2 was 0.15% by weight.

[Comparative Example 3]
An autoclave with a stirrer was charged with 792 g of cyclohexane, 0.71 mmol of tetramethylethylenediamine, 76.3 g of 1,3-butadiene, 28.7 g of styrene, and 0.144 g of bis (diethylamino) methylvinylsilane under a nitrogen atmosphere, and then n-. 0.51 mmol of butyllithium was added, and polymerization was started at 60 ° C. After continuing the polymerization reaction for 60 minutes and confirming that the polymerization conversion rate was in the range of 95% to 100%, the amount of methanol corresponding to twice the molar amount of n-butyllithium used as the polymerization inhibitor was used. Was added to obtain a solution containing a conjugated diene-based rubber. In this solution, 0.15 part of anti-aging agent (trade name "Irganox 1520L", manufactured by BASF) was added to 100 parts of conjugated diene rubber, and extension oil (trade name "Aromax T-DAE"). JX Nikko Nisseki Energy Co., Ltd.) was added in 37.5 parts to 100 parts of conjugated diene rubber, the solvent was removed by steam stripping, and the mixture was vacuum dried at 60 ° C. for 24 hours to form a solid state. Conjugated diene rubber was obtained. The weight average molecular weight (Mw) of the obtained conjugated diene rubber of Comparative Example 3 was 420,000, the styrene monomer unit content was 27% by weight, and the vinyl bond content was 59% by weight. Further, the content of the bis (diethylamino) methylvinylsilane monomer unit in the obtained conjugated diene rubber of Comparative Example 3 was 0.15% by weight.

[Manufacturing and evaluation of rubber compositions and crosslinked rubber products]
In a brabender type mixer having a capacity of 250 ml, 137.5 parts of the conjugated diene rubber of Example 1 (100 parts as a rubber component) is kneaded for 30 seconds, and then silica (manufactured by Rhodia, trade name "Zeosil1115MP") is kneaded. 1. Add 50 parts and 6.0 parts of bis (3- (triethoxysilyl) propyl) tetrasulfide (manufactured by Degussa, trade name "Si69") as a silane coupling agent, starting at 110 ° C. After kneading for 5 minutes, 25 parts of silica (manufactured by Rhodia, trade name "Zeosil1115MP"), 3 parts of zinc oxide, 2 parts of stearic acid and anti-aging agent: N-phenyl-N'-(1,3-dimethylbutyl)- Two parts of p-phenylenediamine (manufactured by Ouchi Shinko Kagaku Kogyo Co., Ltd., trade name "Nocrack 6C") were added and kneaded for another 2.5 minutes, and the kneaded product was discharged from the mixer. The temperature of the kneaded product at the end of kneading was 150 ° C. The kneaded product was cooled to room temperature and then kneaded again in a lavender type mixer for 2 minutes with 110 ° C. as the starting temperature, and then the kneaded product was discharged from the mixer. Then, in an open roll at 50 ° C., 1.40 parts of sulfur, a cross-linking accelerator: N-tert-butyl-2-benzothiazolyl sulphenamide (trade name "Noxeller NS-P"), was added to the obtained kneaded product. By adding 1.2 parts of Ouchi Shinko Kagaku Kogyo Co., Ltd. and 1.2 parts of 1,3-diphenylguanidine (trade name "Noxeller D", manufactured by Ouchi Shinko Kagaku Kogyo Co., Ltd.) and kneading them. A rubber composition was obtained.
Then, the obtained rubber composition was formed into a sheet with an open roll at 50 ° C., and at this time, the roll adhesion of the rubber composition was evaluated according to the above method. The results are shown in Table 1.
Further, the obtained sheet-shaped rubber composition was press-crosslinked at 160 ° C. for 20 minutes to prepare a test piece of the rubber crosslinked product, and the test piece was used for wet grip property, low heat generation, and maneuvering. The stability was evaluated. The results are shown in Table 1.

Further, for the conjugated diene-based rubbers of Examples 2 to 7 and Comparative Examples 1 to 3, rubber compositions were prepared in the same manner, the roll adhesion of the rubber composition was evaluated, and the same was performed. , A test piece of a rubber crosslinked product was prepared, and wet grip property, low heat generation property, and steering stability were evaluated. The results are shown in Table 1.

[Evaluation of Examples 1 to 7 and Comparative Examples 1 to 3]
From Table 1, a polymer block (A) containing an isoprene monomer unit as a main component and a polymer block (B) containing a 1,3-butadiene monomer unit as a main component are provided in the polymer chain. In addition, it has a unit of a vinyl compound containing a functional group capable of interacting with silica, and the weight average molecular weight of the polymer block (A) and the total weight average molecular weight of the conjugated diene rubber are in a predetermined range. The conjugated diene-based rubber in the above is effectively suppressed from adhering to a roll in the case of a rubber composition, whereby excellent processability can be realized, and further, it can be obtained by using this. The rubber crosslinked product had low heat generation, excellent steering stability, and further excellent wet grip properties (Examples 1 to 7).
On the other hand, when a conjugated diene rubber having no unit of a vinyl compound containing a functional group capable of interacting with silica is used in the polymer chain, the obtained rubber composition adheres to the roll. The rubber cross-linked product obtained was inferior in low heat generation and steering stability (Comparative Example 1).
Similarly, when a conjugated diene rubber having a polymer block (A) containing an isoprene monomer unit as a main component and having an excessively small weight average molecular weight is used, or a conjugated diene rubber having no polymer block (A) is used. Even when used, the obtained rubber composition was remarkably adhered to the roll, and the obtained rubber crosslinked product was inferior in low heat generation and steering stability (Comparative Examples 2 and 2). 3).

[Example 8]
In Example 2, N, N-dimethylaminopropyl acrylamide 0.35 mmol, in 3 [Bis (trimethylsilyl) amino] propyl (dimethoxy) (methyl) silane (the general formula ^{(7), R 12} = a trimethylene group, X ¹⁵ , X ¹⁶ = methoxy group, X ¹⁷ = methyl group, X ¹⁸ , X ¹⁹ = trimethylsilyl group compound) Solid conjugated diene rubber in the same manner as in Example 2 except that it was changed to 0.35 mmol. Got The weight average molecular weight (Mw) of the obtained conjugated diene rubber of Example 8 was 482,000, the styrene monomer unit content was 27% by weight, and the vinyl bond content was 58% by weight. Further, the content of the bis (diethylamino) methylvinylsilane monomer unit in the obtained conjugated diene rubber of Example 8 was 0.15% by weight.

[Example 9]
In Example 2, 0.35 mmol of N, N-dimethylaminopropyl acrylamide was added to 2,2-dimethoxy-1- [3- (trimethoxysilyl) propyl] -1,2-azacilolidine (in the above general formula (7)). , R ¹² = trimethylene group, X ¹⁵ , X ¹⁶ = methoxy group, X ¹⁸ = 3- (trimethoxysilyl) propyl group, X ¹⁷ and X ¹⁹ instead of silicon atom and nitrogen atom in the above general formula (7). A solid conjugated diene rubber was obtained in the same manner as in Example 2 except that the compound was changed to 0.35 mmol. The weight average molecular weight (Mw) of the obtained conjugated diene rubber of Example 9 was 624,000, the styrene monomer unit content was 27% by weight, and the vinyl bond content was 58% by weight. Further, the content of the bis (diethylamino) methylvinylsilane monomer unit in the obtained conjugated diene rubber of Example 9 was 0.15% by weight.

For the conjugated diene-based rubbers of Examples 8 and 9, rubber compositions were prepared in the same manner as in Example 1, and the roll adhesion of the rubber composition was evaluated, and similarly, the rubber crosslinked product was evaluated. Test pieces were prepared and evaluated for low heat generation and steering stability. The results are shown in Table 2. For comparison, the results of Comparative Example 1 are also shown in Table 2.

[Evaluation of Examples 8 and 9]
From Table 2, even when the compound represented by the above general formula (7) is used as the heteroatom-containing compound, the adhesion to the roll is effectively suppressed in the case of the rubber composition as well. As a result, excellent workability can be realized, and further, the rubber crosslinked product obtained by using the same has excellent low heat generation and steering stability (Examples 8 and 9).

[Example 10]
Except that in Example 1, 0.144 g of bis (diethylamino) methylvinylsilane was changed to 0.135 g of m / p-pyrrolidinoethylstyrene (mixture of m-pyrrolidinoethylstyrene and p-pyrrolidinoethylstyrene). Obtained a solid conjugated diene-based rubber in the same manner as in Example 1. The weight average molecular weight (Mw) of the obtained conjugated diene rubber of Example 10 was 470,000, the styrene monomer unit content was 27% by weight, and the vinyl bond content was 58% by weight. Further, the content of m / p-pyrrolidinoethylstyrene monomer unit in the obtained conjugated diene rubber of Example 10 was 0.13% by weight.

[Comparative Example 4]
In Comparative Example 3, a solid conjugated diene rubber was obtained in the same manner as in Comparative Example 3 except that 0.144 g of bis (diethylamino) methylvinylsilane was changed to 0.135 g of m / p-pyrrolidinoethylstyrene. .. The weight average molecular weight (Mw) of the obtained conjugated diene rubber of Comparative Example 4 was 246,000, the styrene monomer unit content was 27% by weight, and the vinyl bond content was 59% by weight. Further, the content of the pyroridinoethyl styrene monomer unit in the obtained conjugated diene rubber of Comparative Example 4 was 0.13% by weight.

For the conjugated diene-based rubbers of Example 10 and Comparative Example 4, a rubber composition was prepared in the same manner as in Example 1, and the roll adhesion of the rubber composition was evaluated. A test piece of the crosslinked product was prepared, and low heat generation and steering stability were evaluated. The results are shown in Table 3.

[Evaluation of Example 10 and Comparative Example 4]
From Table 3, even when m / p-pyrrolidinoethyl styrene was used as the vinyl compound containing a functional group capable of interacting with silica, similarly, when it was made into a rubber composition, it was applied to a roll. Adhesion is effectively suppressed, which makes it possible to realize excellent workability, and further, the rubber crosslinked product obtained by using this is excellent in low heat generation and steering stability. (Example 10).
On the other hand, even when m / p-pyrrolidinoethylstyrene is used as the vinyl compound containing a functional group capable of interacting with silica, the polymer block (A) containing an isoprene monomer unit as a main component. When a conjugated diene-based rubber having no is used, the obtained rubber composition is remarkably adhered to the roll, and the obtained rubber crosslinked product is inferior in low heat generation and steering stability. (Comparative example 4).

[Example 11]
830 g of cyclohexane, 1.28 mmol of tetramethylethylenediamine, 80.3 g of 1,3-butadiene, 29.7 g of styrene, and 0.132 g of bis (diethylamino) methylvinylsilane were charged into an autoclave with a stirrer under a nitrogen atmosphere, and then the above production was performed. The polymer block (A2) having an active terminal obtained in Example 2 was added in an amount of 0.80 mmol in terms of lithium atom content, and polymerization was started at 60 ° C. It was continued for 60 minutes the polymerization reaction, the polymerization conversion rate confirms that it is now in the range of 95% 100%, N, at the N- dimethylaminopropyl acrylamide (the general formula ^{(8), R} 19, R ²⁰ , R ²¹ , R ²² = hydrogen atom, R ²³ = trimethylene group, R ²⁴ , R ²⁵ = methyl group compound) 0.30 mmol was added and reacted for 15 minutes. Then 0.30 mmol of 3-diethylaminopropyltrimethoxysilane was added and reacted for 30 minutes. Then, as a polymerization inhibitor, methanol corresponding to twice the mole of n-butyllithium used was added to obtain a solution containing a conjugated diene rubber. To this solution, 0.15 part of an anti-aging agent (trade name "Irganox 1520L", manufactured by BASF) was added to 100 parts of conjugated diene rubber, and then the solvent was removed by steam stripping to remove the solvent at 60 ° C. The mixture was vacuum-dried for 24 hours to obtain a solid conjugated diene-based rubber. The weight average molecular weight (Mw) of the obtained conjugated diene rubber of Example 11 was 380,000, the styrene monomer unit content was 27% by weight, and the vinyl bond content was 57% by weight. The content of bis (diethylamino) methylvinylsilane monomer unit in the obtained conjugated diene rubber of Example 11 was 0.12% by weight.

[Example 12]
830 g of cyclohexane, 1.28 mmol of tetramethylethylenediamine, 80.3 g of 1,3-butadiene, 29.7 g of styrene, and 0.066 g of bis (diethylamino) methylvinylsilane were charged into an autoclave with a stirrer under a nitrogen atmosphere, and then the above production was performed. The polymer block (A2) having an active terminal obtained in Example 2 was added in an amount of 0.80 mmol in terms of lithium atom content, and polymerization was started at 60 ° C. The polymerization reaction was continued for 60 minutes, and after confirming that the polymerization conversion was in the range of 95% to 100%, 0.30 mmol of N-phenylpyrrolidone was added and the reaction was carried out for 15 minutes. Next, the polyorganosiloxane represented by the above formula (9) was added so as to be 0.33 mmol in terms of the number of repeating units of −Si—O—, and the reaction was carried out for 30 minutes. Then, as a polymerization inhibitor, methanol corresponding to twice the mole of n-butyllithium used was added to obtain a solution containing a conjugated diene rubber. To this solution, 0.15 part of an anti-aging agent (trade name "Irganox 1520L", manufactured by BASF) was added to 100 parts of conjugated diene rubber, and then the solvent was removed by steam stripping to remove the solvent at 60 ° C. The mixture was vacuum-dried for 24 hours to obtain a solid conjugated diene-based rubber. The weight average molecular weight (Mw) of the obtained conjugated diene rubber of Example 12 was 506,000, the styrene monomer unit content was 26% by weight, and the vinyl bond content was 58% by weight. Further, the content of bis (diethylamino) methylvinylsilane monomer unit in the obtained conjugated diene rubber of Example 12 was 0.060% by weight.

[Comparative Example 5]
An autoclave with a stirrer was charged with 830 g of cyclohexane, 1.28 mmol of tetramethylethylenediamine, 80.3 g of 1,3-butadiene, 29.7 g of styrene, and 0.132 g of bis (diethylamino) methylvinylsilane under a nitrogen atmosphere, and then n-. 0.80 mmol of butyllithium was added, and polymerization was started at 60 ° C. The polymerization reaction was continued for 60 minutes, and after confirming that the polymerization conversion was in the range of 95% to 100%, 0.30 mmol of N-phenylpyrrolidone was added and the reaction was carried out for 15 minutes. Then, 0.30 mmol of 1,3,5-tris (trimethoxysilylpropyl) isocyanurate was added and reacted for 30 minutes. Then, as a polymerization inhibitor, methanol corresponding to twice the mole of n-butyllithium used was added to obtain a solution containing a conjugated diene rubber. To this solution, 0.15 part of an anti-aging agent (trade name "Irganox 1520L", manufactured by BASF) was added to 100 parts of conjugated diene rubber, and then the solvent was removed by steam stripping to remove the solvent at 60 ° C. The mixture was vacuum-dried for 24 hours to obtain a solid conjugated diene-based rubber. The weight average molecular weight (Mw) of the obtained conjugated diene rubber of Comparative Example 5 was 385,000, the styrene monomer unit content was 27% by weight, and the vinyl bond content was 58% by weight. The bis (diethylamino) methylvinylsilane monomer unit content in the obtained conjugated diene rubber of Comparative Example 5 was 0.12% by weight.

[Comparative Example 6]
After charging 830 g of cyclohexane, 1.28 mmol of tetramethylethylenediamine, 0.61 mmol of piperidine, 80.3 g of 3-butadiene, 29.7 g of styrene, and 0.066 g of bis (diethylamino) methylvinylsilane in an autoclave with a stirrer under a nitrogen atmosphere. , N-Butyllithium was added in an amount of 0.80 mmol, and polymerization was started at 60 ° C. The polymerization reaction was continued for 60 minutes, and after confirming that the polymerization conversion was in the range of 95% to 100%, 0.30 mmol of N, N-dimethylaminopropyl acrylamide was added and the reaction was carried out for 15 minutes. Then, 0.30 mmol of 1,3,5-tris (trimethoxysilylpropyl) isocyanurate was added and reacted for 30 minutes. Then, as a polymerization inhibitor, methanol corresponding to twice the mole of n-butyllithium used was added to obtain a solution containing a conjugated diene rubber. To this solution, 0.15 part of an anti-aging agent (trade name "Irganox 1520L", manufactured by BASF) was added to 100 parts of conjugated diene rubber, and then the solvent was removed by steam stripping to remove the solvent at 60 ° C. The mixture was vacuum-dried for 24 hours to obtain a solid conjugated diene-based rubber. The weight average molecular weight (Mw) of the obtained conjugated diene rubber of Comparative Example 6 was 245,000, the styrene monomer unit content was 26% by weight, and the vinyl bond content was 59% by weight. The content of bis (diethylamino) methylvinylsilane monomer unit in the obtained conjugated diene rubber of Comparative Example 6 was 0.060% by weight.

[Comparative Example 7]
830 g of cyclohexane, 1.28 mmol of tetramethylethylenediamine, 80.3 g of 1,3-butadiene, and 29.7 g of styrene were charged into an autoclave with a stirrer under a nitrogen atmosphere, and then the polymer block having the active terminal obtained above was charged. 0.80 mmol of (A2) was converted into a lithium atom content, and polymerization was started at 60 ° C. After continuing the polymerization reaction for 60 minutes and confirming that the polymerization conversion was in the range of 95% to 100%, 0.61 mmol of 1,3,5-tris (trimethoxysilylpropyl) isocyanurate was added. , 30 minutes. Then, as a polymerization inhibitor, methanol corresponding to twice the mole of n-butyllithium used was added to obtain a solution containing a conjugated diene rubber. To this solution, 0.15 part of an anti-aging agent (trade name "Irganox 1520L", manufactured by BASF) was added to 100 parts of conjugated diene rubber, and then the solvent was removed by steam stripping to remove the solvent at 60 ° C. The mixture was vacuum-dried for 24 hours to obtain a solid conjugated diene-based rubber. The weight average molecular weight (Mw) of the obtained conjugated diene rubber of Comparative Example 7 was 499,000, the styrene monomer unit content was 28% by weight, and the vinyl bond content was 58% by weight.

For the conjugated diene-based rubbers of Examples 11 and 12 and Comparative Examples 5 to 7, test pieces of crosslinked rubber were prepared in the same manner as in Example 1 and evaluated for low heat generation. The results are shown in Table 4.

[Evaluation of Examples 11 and 12, Comparative Examples 5 to 7]
From Table 4, even when two kinds of compounds are used as heteroatom-containing compounds and reacted in sequence, the rubber crosslinked product obtained by using the conjugated diene rubber thus obtained is similarly low in heat generation. It was excellent in properties (Examples 11 and 12). Further, also in Examples 11 and 12, similarly to Examples 1 to 7, the rubber composition is effectively suppressed from adhering to the roll, and is excellent in processability. Furthermore, it can be said that the rubber crosslinked product obtained by using this is excellent in steering stability in addition to low heat generation.
On the other hand, even when two kinds of compounds are used as the heteroatom-containing compound, when a conjugated diene rubber having no polymer block (A) containing an isoprene monomer unit as a main component is used, or when silica is used. When the vinyl compound containing an interactable functional group was not copolymerized, the low heat build-up was inferior (Comparative Examples 5 to 7).

Claims (10)

A conjugated diene-based rubber comprising a polymer block (A) containing an isoprene monomer unit as a main component and a polymer block (B) containing a 1,3-butadiene monomer unit as a main component.
At least one of the polymer block (A) and the polymer block (B) contains a unit of a vinyl compound containing a functional group capable of interacting with silica.
The weight average molecular weight (Mw) of the polymer block (A) is in the range of 1,000 to 30,000, and the overall weight average molecular weight (Mw) of the conjugated diene rubber is 50,000 to 5,000. Conjugated diene rubber in the range of 000. Claimed that the content ratio of the unit of the vinyl compound containing a functional group capable of interacting with the silica is 0.01 to 20% by weight with respect to all the monomer units constituting the conjugated diene rubber. Item 2. The conjugated diene-based rubber according to Item 1. The conjugated diene rubber according to claim 1 or 2, wherein at least one of the polymer block (A) and the polymer block (B) contains an aromatic vinyl monomer unit. The conjugated diene rubber according to any one of claims 1 to 3, which has a heteroatom-containing functional group at the end of the polymer block (B). The method for producing a conjugated diene rubber according to any one of claims 1 to 4, wherein the monomer (a) containing isoprene is polymerized with a polymerization initiator in an inert solvent to have an active terminal. The step of forming the polymer block (A) and
The polymer block (A) having the active terminal and the monomer (b) containing 1,3-butadiene are mixed to continue the polymerization reaction, and the polymer block (A) and the polymer block (B) are continued. ) To obtain a conjugated diene-based polymer chain having an active terminal.
A method for producing a conjugated diene-based rubber, wherein at least one of the monomer (a) or the monomer (b) contains a vinyl compound containing a functional group capable of interacting with silica. The method for producing a conjugated diene rubber according to claim 5, further comprising a step of reacting a heteroatom-containing compound with the active end of the conjugated diene polymer chain having the active end. A rubber composition containing silica and a rubber component containing the conjugated diene-based rubber according to any one of claims 1 to 4. The rubber composition according to claim 7, further comprising a cross-linking agent. A rubber crosslinked product obtained by cross-linking the rubber composition according to claim 7 or 8. A tire containing the crosslinked rubber product according to claim 9.